Five Teams That Should Not Scare Duke In March

Duke fans, I've noticed, have a tendency to be of the self-hating variety. Threads at Duke Basketball Report are filled with skepticism for (supposedly) one's own team, which seems like it just doesn't translate well into pleasurable fan experiences. Some fans even go as far as concocting reasons why a win in a given game is not a big deal: I even saw a fan state that "some years the best team doesn't win it all; if Duke won the national championship, this would be one of those years." How sad a fan existence is that?

To combat the rampant pessimism, this post will identify the types of NCAA tournament teams Duke matches up extremely well against. I will examine whether some of the teams rated top in the country by pollsters and bracketologists are also the types of teams that match up well against Duke in tempo-free statistics. Here I will look at teams that match up poorly against Duke; later I will take a look at some "scarier" teams. My approach is to examine a path towards the National Championship that includes possible opponents at each level of the NCAA Tournament, and which teams/types of teams Duke would love to see. It is unlikely that Duke will have trouble with its first round opponent this year, so that leaves five rounds, and five example teams.

Clearly, this analysis involves looking at precisely zero video. The only team I have consistently watched all year is Duke; I may have tuned into a game here or there for other teams, but that one game could bias my thoughts on non-ACC teams. From the tempo-free perspective, there are a number of things Duke does extremely well:

1) Offensive Rebounding (7th in nation at 40.7%). Brian Zoubek is no longer Duke's best-kept secret weapon, and his improved offensive efficiency rating over the last few games complements his best-in-the-nation offensive rebounding ability.

2) Free Throw Percentage (8th in nation at 75.9%). While other teams can't really control how Duke does from the line, they can certainly be a team that fouls a lot, sending Duke to the line for some free points.

3) Three-Point Shooting Defense (1st in nation at 26.7%). Mid-major teams which lack size and rely on the three-pointer are going to have long nights against Duke in March.

4) Lack of Turnovers (16.4% of possessions, 11th in nation). Duke's turnover rate has been particularly excellent over their last few ACC games (and would be even lower if not for several turnovers by the bench players in garbage time against Virginia).

5) Height. Pomeroy lists two kinds of height on his statsheet: The raw number in inches (Duke's average height is 2nd in the nation at 79.0"). Clearly, this should be weighted by playing time, and Pomeroy does this: he points out that height is correlated to offensive efficiency with r-squared = 0.27, with r-squared = 0.38 on the defensive end. Duke's "Effective Height" is +4.9, meaning they are about five inches taller than the average Division-1 team. Here are the tallest teams in the nation, and Duke has already beaten four of the top ten!

Last week, I pointed out the aspects of the tempo-free analysis that Duke struggles with, and not much has changed so refer to that post for Duke's weaknesses.

Looking at the 7,8,9,and 10 seeds in Joe Lunardi's latest bracketology is a good place to find teams Duke is likely to see in the second round of the tournament. There are a bunch of ACC teams there, but we can leave them out since the committee does like to put teams from the same conference on collision courses before the regional final. Which of these teams sticks out as matching up poorly against Duke?

1 (Thirsty Thirty-Two) Oklahoma State. Picked to be a #8 seed by Joe Lunardi, and firmly in the "Also Receiving Votes" portion of both human polls, the Cowboys are a possible second-round opponent for Duke. Their overall offensive (112.8; 31st) and defensive (94.1, 62nd) efficiencies are about the middle of the pack for possible NCAAT teams, as you might expect for a team with a middle-seed. When broken down into component factors, there's a lot to like about this team from a Duke perspective. First of all, they are a short team, with an effective height more than an inch below the D-1 average; the tallest player on the roster is 6-8 Junior Matt Pilgrim, who sees less than 40% playing time.

The most convincing matchup for Duke comes with shot selection. Oklahoma State is near the top of the pile in relying on the three-point shot: 32.7% of their points come from behind the arc, which is 45th in the nation (the highest among possible NCAAT teams). Further, they are not particularly good at making three-pointers, shooting just 35.6%, barely in the top third of all D-1 teams. Finally, the Cowboys struggle to grab offensive rebounds: a rate of 30.2% of their missed shots places them 264th in the nation. The combination of chucking up threes, not making a lot, and struggling to rebound is a strategy that plays very poorly against the Blue Devils, who have superior rebounding and 3-point defense.

2 (Sweet Sixteen) Pittsburgh. This is a team that is slated to be seeded in the 3-5 range, and therefore is a possible Sweet-Sixteen matchup, and one that the tempo-free stats say would be good for Duke. The biggest reason that jumps out is, once again, height. Pittsburgh has an effective height of a full inch below average, especially at guard and forward. They do have 6-10 center Gary McGee, who plays nearly 60% of the time, but who is not much of a factor offensively. Defensively, McGee has a good block rate and a good defensive rebounding ability, so most of Duke's height advantage in this one comes from Kyle Singler and Jon Scheyer, who tower over their likely defensive counterparts.

One thing Duke would not be doing in a game with Pittsburgh is wasting offensive possessions. While the Panthers are good at limiting their opponent's eFG% (44.1; 20th), they are mediocre-to-bad at the other three factors. Duke protects the basketball pretty well on offense, and Pittsburgh rarely forces their opponents into turnovers (Defensive turnover rate: 16.8, 335th). Pitt also don't have much success on the defensive boards (DR% 68.9, 106th), which once again sets up the scenario of Duke dominating the offensive glass and making every possession count.

Pitt also plays a rather plodding pace (62.4 poss/game, 325th), and has a rather heavy reliance on getting to the free throw line to make their points (23.9% of points come from the charity stripe, 42nd most in the nation). If this game were played in November, this could have come as an advantage for Pitt, but Duke has reduced their fouls in recent weeks, with good results. The tempo-free stats don't say much about the "quick guards" factor, but Pitt does have a high percentage of their baskets accompanied by assists (67.1%, 4th). If this is the signature of a quick team using a lot of backdoor cuts, that could potentially hurt Duke's defense, but this signal is not nearly as strong as the possibility of Duke dominating Pitt on the offensive glass.

3 (Elite Eight) New Mexico. I'm all for giving respect to mid-major teams-- when they deserve it. Ranked #8 in the nation in the polls, #7 in RPI, and given a #2 seed in Joe Lunardi's latest bracketology, things are looking up for the Lobos. With the clear caveat that I have never seen them play, I'm not really sure what all the fuss is about. Ken Pomeroy is with me, and has used New Mexico to drive home a point: as long as the NCAA fails to consider Margin of Victory when making tournament picks/seeding decisions, they will continue to not pick/seed poorly the best teams in the country. Case in point: The Sagarin rankings, which have two parts, one (ELOCHESS) that only considers wins and losses; New Mexico is ranked #8. But when points scored/allowed is taken into account (in the PREDICTOR), New Mexico drops to #33. So, really, most elite teams this year should not be scared of New Mexico.

Duke has some specific advantages, though. One is, again, height, and the Lobos are an average team (Effective height +0.1"). New Mexico has been pretty good on the defensive boards (DR% 72.7; 11th best), but in the components for mid-majors, where most teams are short, it requires a little digging to see how they did against tall teams. Indeed, New Mexico's worst game on the defensive boards was their loss at San Diego State, a team that is only elite at one thing: offensive rebounding (they are ranked 6th in the nation for this component). UNM's best rebounder is Darrington Hobson, who at 6-7, 205 is not the kind of player you really want battling against Brian Zoubek...

New Mexico has other weaknesses that play into Duke's strengths, such as an above-average reliance on three-pointers, playing a generally slow pace, and with inexperienced players (ranked 241st Pomeroy's experience stat, versus Duke, ranked 81st in experience). However, if New Mexico were given a 2-seed, they wouldn't see Duke until the regional-final at the earliest, and the stats suggest that the Lobos will lose well before that point.

4 (Final Four) Villanova. 'Nova leaves the most recent bitter taste in the mouth for Duke fans. For this reason, a Duke fan may not be able to see passed some simple truths: a) Duke, in 09-10, has a better, taller, more versatile team than in 08-09 and b) Villanova's team is about the same as it was last year. Yes, they still have "quick guards" although the tempo-free analysis doesn't really see much other than their shooting percentages and overall efficiency; Reynolds, Fisher, and Pena are all rated above 115.0, which is pretty good. The Wildcats are ranked highly enough that it would be unlikely for Duke to face them this tournament until the Final Four, so we will consider them here.

The tempo-free stats don't pull out a whole lot of things that Villanova does really well. Their free throw percentage (75.6%) is comparable to Duke's, and they pull in a good number of offensive rebounds, especially considering their effective size (which is basically average). While teams at the top of the rankings are going to be fairly good, what we're looking for is whether Villanova's particular strengths and weaknesses lie within Duke's (as defined by tempo-free stats). The biggest red flag is pace: Villanova averages 75.8 possessions/game (11th), which we identified as a potential pitfall for a Duke team that averages just 67.3 poss/g (178th). Villanova also has a balanced attack, not relying too much on 3-pointers, 2-pointers, or foul shots.

But there are more red flags for Villanova. First and foremost: they foul. A lot. A defensive free-throw-rate of 49.7 is the ninth-highest in the nation, and Duke's elite free throw ability will give the Blue Devils lots of free points in this matchup. Villanova has had some atrocious games (at Georgetown and vs UConn) in which the opposing team shot more free throws than they made field goals! That is not a very good winning strategy, especially when in general your defense, relative to other supposed NC-contenders, is lacking. They allow a higher-than-average percentage of 3-point shots (3PTA/FGA = 38.2; 316th lowest), and their opponents make an above-average amount (3PT% against = 33.4; 140th). They are not particularly great on the defensive boards (DR% = 68.5; 122nd), and they don't force many turnovers (Defensive Turnover Rate = 22.0; 100th). It would only take an average-shooting night for Duke to win this one handily.

5 (National Championship Game) Kansas State. Okay, I will fully admit that this selection is a little bit of cheating, so let me explain. Should Duke get to the National Championship game, the range of teams they could face is necessarily much better than the range of teams they could face in the earlier rounds. Examining the rest of the Top 10 in the human and computer polls, there are a lot of teams that make for match-ups that are extremely tough to call from a tempo-free perspective, because each team is pretty good at a lot of things. For teams like Syracuse and Kentucky, there aren't any aspects that scream out "Duke is good at this aspect and the opponent sucks at that aspect!" Or vice versa. There are also teams for which there is convincing evidence that Duke would struggle... but that is for the next post. Finally, picking a Hummel-less Purdue just seems too easy, and without Hummel they probably don't make it to the title game anyway. So of the consensus top teams, the one against which Duke would have the easiest time is Kansas State.

The component of Kansas State's game that speaks the loudest is the fouls. I would imagine that most Kansas State games take three hours or more, with how often the Wildcats (Free Throw Rate: 53.3; 2nd) and their opponents (Free Throw Rate Allowed: 46.7, 309th) spend on the free throw line. Kansas State gets more than a quarter of their points from free throws, way more than Pittsburgh (see above), and the 19th most in the nation. However, once they get there they only shoot 66%, with only one of their regulars (Jacob Mullen) north of 75% individually.

They get around all this fouling by having a revolving door for a frontcourt. Three players (6-9 Wally Judge, 6-10 Luis Colon, and 7-0 Jordan Henriquez-Roberts) each grab just 25% minutes (that's 10 min/game) and each manage to put up foul rates above 7.0/40 minutes. The rest of the frontcourt minutes belong to 6-8 Curtis Kelly, who has decent defensive numbers, but isn't a standout offensive star.

From the team perspective, Kansas State does a lot of similar things to Duke. They are one of the few teams better than the Blue Devils on the offensive glass, grabbing 41.2% of their missed shots, which are frequent (since they shoot 36% from beyond the arc and 50% inside it, both rather mediocre). However, Kansas State, whether by design or by ability, struggles on the defensive glass, much more so than Duke does. This has a recipe for being a physical game, in which both teams finish possessions either with offensive rebounds, putting back missed shots, or by heading to the free throw line. There is one wrinkle that makes the comparison less symmetrical: Kansas State has a high turnover rate (21.4; 216th), and while Duke's defensive turnover rate is not great (22.1; 79th), the turnover battle certainly tips the Blue Devils' way. Overall, in a foul-shooting battle, Duke has the definite advantage, given their much higher free throw abilities. The game would come down to which team lost their best interior player due to foul trouble.

This window into Duke's potential road to the national championship is far from perfect. It leaves out a lot of factors, some that are "intangible" and others that are tangible but simply not measured (unless someone wants to watch thousands of hours of tape to quantify how "quick" certain team's guards are). And while my cherry-picking of teams may seem highly beneficial to Duke, I hope that I've at least illustrated that there are teams out there against which Duke stacks up against mightily. The tempo-free statistics say that Duke is the best team in the nation, by a fairly wide margin. While self-hating fans and Duke-haters alike may not consider Duke to be on their list of "scary" teams, there is clearly room for optimism in Durham.

Duke Weaknesses (Perceived and Real)

Clearly, this year's Duke team is neither entitled nor even favored to win the National Championship. The widely respected human opinion polls put, at time of writing, half a dozen teams above a Duke team that has failed to receive a single first-place vote this entire season. Clearly, something scatters the blue sunshine. There are many common memes surrounding Duke, though only a few of them actually apply to this years' team. Let's take a look at some of the common criticisms levied against this year's Duke squad, analyzed from a tempo-free perspective (statistics, as always, from Ken Pomeroy).

1) Duke has played a soft schedule. If we go based on the tempo-free stats, nothing could be further from the truth. Pomeroy ranks Duke's schedule second in the nation, behind West Virginia. Sure, their non-conference schedule is ranked 83rd, but take a look at the teams on top of the non-conference SOS rankings: other than Butler, none of the top 20 have a prayer at an at-large tournament bid. And a number of the teams up top are probably there because they played Duke... this criticism is tired and should be sent to the land of misfit memes.

Making the argument worse is the observation that not only does Duke have the #3 offense in raw efficiency (1.17 points/possession), they have accomplished such lofty efficiency against a harder slate of defenses than anyone in the nation (adjusted efficiency of defenses Duke has played: 0.95 points/possession).

Taken more subjectively, Duke will play 15 non-conference games this regular season (counting Thursday's game against Tulsa). Of these, as many as 7 teams could make the NCAA tournament; what is a better preparation for NCAA tournament play than contests against teams that will actually be there? For comparison, Duke is #2 in the Sagarin strength of schedule as well, and played the fifth-toughest slate in this version of RPI.

2) Lack of backcourt depth. It seems only yesterday that the meme was about the lack of frontcourt depth (well, last year anyway). Assuming that Kyle Singler counts as a guard, Duke's main men play a ton of minutes, while backup shooting guard Andre Dawkins has struggled in limited minutes. I have a problem with this criticism on a number of levels. Part of this argument comes from the same area as the Duke Fade, which is that too many minutes are given to the Big Three. Here's the tempo-free stats.

Player......%Minutes........ORtg....%Possessions
Scheyer.........91.6.............130.7.........23.1
Singler.........89.5............114.3.........23.1
Smith.........82.2.............117.5.........23.1

First of all, pretty cool that all three are used in the same percentage of possessions. Second, if you have three players capable of contributing those massive tempo-free player ratings, why would it be a bad thing to play them all the time? If a player was used so much that they tired in-game, his offensive rating would plummet, due to the extended number of possessions played. Duke's top three men (by % minutes played) have a higher combined rating (362.5) than the top three men on Kansas (358.5), Syracuse (333.4), Purdue (343.1), West Virginia (354.4) and Kentucky (334.5), to pick a few. Scheyer/Singler/Smith are doing it in far more minutes than any of those teams, save perhaps WV, who do get 80%+ minutes from Butler and Jones.

For another avenue of argument, I shall paraphrase what I overheard this morning on 99.9 The Fan in Raleigh: "While Duke has the best trio of players in the country, what happens when they are all shut down?" This, of course, has an easy answer: Duke would lose. The better question is: "what's the likelihood of all three being shut down?" The three Duke stars average a combined 53.8 points/game; the fewest they've scored, combined, was 41 in the Preseason NIT championship win over UConn. In Duke's four losses, the trio has averaged about the same amount, and scored a combined 61 points in the loss at Georgetown. Indeed, it seems that Duke's wins will come down to how many points they can drag out of their frontcourt. Which leads to...

3) Duke has no talent in the frontcourt. I should hope that the last three games would silent anyone who would make such a bold claim. There is clearly some talent in the frontcourt, and that is in the (massive) form of Brian Zoubek. The man who makes girls swoon so hard that their marriage proposal signs are upside down has averaged nearly a double-double (9.7 points, 12.7 rebounds) in those games. With his new-found ability to avoid foul trouble, Zoubek has slipped back above the 40% minutes played mark. This finds him back atop the nation in offensive rebounding. Let's nail that home for the readers too lazy to click on the link:

Category: Percentage of a team's missed shots rebounded by a player while he's on the court.
Qualification: 40% of a team's minutes played (that's about 16 min/game, ignoring OTs)

1. Brian Zoubek, Duke 23.0%
2. Demarcus Cousins, Kentucky, 22.8%
3. Anthony Johnson, Fairfield, 17.4%

So, other than the stud freshman at Kentucky, no one is even close to Brian Zoubek in offensive rebounding ability. Against Maryland, Zoubek used missed shots by the Big Three to have an amazing offensive night, scoring 16 points with 17 rebounds (8 OR). Then, against Virginia Tech, Zoubek benefited from Duke's cold shooting for another 16 rebounds (8 OR). This time he tended to kick the ball out to open men, including two assists on Nolan Smith three-pointers.
The tempo-free world is only six years old, but in that time, only three players have had an OR% above 21%: DeJuan Blair was at 23.6% last year. (The next highest season total is 20.8%).

Of course, there's more to the frontcourt than Zoubek, and the tempo-free stats have mixed feelings about Duke's other big men. Miles Plumlee is a very strong defensive rebounder, and at 22.6% is currently vying for Duke's best defensive rebounding mark since Pomeroy started tracking individual stats in 2005 (Shelden Williams' best was 22.0%). Mason Plumlee currently has the lowest offensive rating on the team (94.5), thanks to a triple-whammy of low effective field goal percentage, small rebounding numbers, and a very high turnover rate. While analysts have been high on Mason's potential, the tempo-free stats haven't shown that this season.

Lance Thomas is generally seen as the "glue" of the 2009-2010 Duke team, and the captain is certainly one of the emotional leaders. As with many in this position, his contributions are said to be "intangible." Indeed, tempo-free statistics don't have much to say about LT. He has an average offensive rating, and the only stat which really stands out is his turnover rate, which is the highest on the team: Duke turns the ball over on 26.1% of his possessions. This could be partially due to Lance, who turns the ball over 1.6 times/game; it could also be unlucky that he's on the court when turnovers occur. Don't view this as a total knock on Thomas, however. These stats of course only include offense, and while Thomas' contribution may not be exactly "intangible" it is certainly "unmeasured" by this system.

Overall, this criticism is still hanging on by a few threads. Clearly, Duke's frontcourt is responsible for a massive number of rebounds, so much so that it can prop up a poor shooting night against many teams. Whether one of the Plumlees or Zoubek can be a viable offensive threat remains to be seen. For now, only Zoubek is impressive from the tempo-free perspective.

For the heck of it, let's throw in:

4) Duke gets all the calls. While pretty hilarious in most seasons, this conspiracy theory has a pretty steep piece of evidence to overcome this year: this season, Duke has a free throw rate (FTA/FGA) of 37.8, which is 171st in the nation, good for almost exactly median. In addition, Duke gets only 21.9% of their points from the charity stripe, good for 119th in the nation. This season, the refs seem to have been paid off by the fans of Kansas State (Free Throw Rate: 53.3) and Wyoming (27% of points from FTs). What Duke does have going for them, however, is free throw percentage: 8th in the nation at 75.9%.

So, what are Duke's real weaknesses, as shown by tempo-free stats?

1) Fouls. As alluded above, Duke struggles more than usual to get to the free throw line, and so cannot benefit as much from their high percentages from the line. While in most years, Duke has multiple players drawing more than 5 fouls per 40 minutes, only Scheyer is above that mark, and no one else is very close.

On the other side of the basketball, committing fouls has been a huge problem, particularly for Brian Zoubek (8.2 Fouls Committed/40 minutes) and Mason Plumlee (7.2 FC/40). In all three of Duke's January losses, they allowed their opponents to get to the free throw line at a rate of about 50 FTA/FGA.

2) Slow Pace On each team's "Game Plan" page, Pomeroy has tables of correlation coefficients. Each of these is a measure of how correlated a particular statistic is with offensive/defensive efficiency. At the moment for Duke, one of these, on offense, is the "pace" of the game, measured by the number of possessions. As Duke's number of possessions goes up, so does their offensive efficiency. For example, Duke's fastest game this season was against Pennsylvania, in which Duke scored 115 points in 75 possessions (Offensive Efficiency: 151.8!) . In Duke's slowest game, at Clemson, the Blue Devils scored just 60 points in 61 possessions, for an efficiency of 98.8. This will definitely be a trend to keep an eye on, should Duke face a team notorious for slow play in March (looking at you, Big Ten).

3) Allowing 2-pointers Duke's defense is ranked 18th in efficiency, but it has it's definite weaknesses. While the Blue Devils are second in the nation in 3-point shooting percentage against (27.4%), they allow opponents to shoot over 45% inside the arc (81st). Put another way, Duke's opponents score 60.8% of their points from 2-point range, which is the 8th most in the nation (to be fair, the 18.4% of opponent's points from beyond the arc is fourth lowest). Duke's strategy clearly makes some sense: it doesn't take a math degree to deduce that 3 > 2. However, some teams are just not built for chucking up treys. This season, Georgetown, NC State, and Wisconsin all used Duke's spread defense to their advantage, scoring backdoor layups and short-range jumpshots.

As the rankings sit today, Duke is the best team in the nation, measured from a tempo-free perspective. They have the best offense, a good defense, and have played a very strong schedule. We've seen that many of the common criticisms of Duke fall apart when seen from the perspective of tempo-free stats. Still, this is a college basketball world without perfection, and while Pomeroy's statistics can help us see that Duke is a little underrated by the human polls, there is still room for improvement as March looms.

The Duke Fade: A Response

Earlier today, Alex Fanaroff of Duke's daily newspaper The Chronicle posted a wonderful article, "Duke Does Decline, Objectively Speaking." It's a refreshing look at basketball in a way that we love here at the Immaculate Inning: using tempo-free statistics. Fanaroff describes the general issue:

1) Duke fades down the stretch.
2) This is due to the starters playing way too many minutes, causing them to get tired.

Fanaroff went into the article expecting to at least debunk #1 as a myth, but ended up finding a strong correlation between Duke's efficiency margin (Offensive Efficiency - Defensive Efficiency), and the number of ACC games played. This suggested that over the last seven years, the data indeed does suggest a Duke Fade. Fanaroff was unable, however, to show that "minutes by starters" had any effect on efficiency margin. Naturally, I was intrigued, and wanted to dial further into the data. Here are a number of issues:

1) Year effects do matter. In his accompanying blog post, Faranoff says "Predictably, most seasons failed to produce robust trends due to the limited sample size, though all seasons from 2004-2009 demonstrated a downward trend." This statement is misleading on two accounts. First of all, here is each year plotted individually, with the linear regression line on each:

True, there is a downward trend most years, and Faranoff does mention that Duke's trend is technically upwards this season. Most seasons, that line is not significant: there is not enough evidence to say that the regression line differs from no slope.

However, the null hypothesis can be rejected in 2004 (r-squared 0.2177, p = 0.04406) and 2008 (r-squared 0.2993, p = 0.01879). Here's my question: if a declining efficiency margin during ACC play is a bad thing, then why did the 2004 team make the Final Four, despite having one of of the few significant in-year declines?

2) Opponents matter. As many folks over at the fine institution of DBR have pointed out, Duke always plays Carolina as its last ACC regular season game. Then, while the early rounds of the ACC tourney may provide a brief dip in competition, Duke almost always advances to the end of the tournament, and they naturally find better teams there. We can look at the effect of Opponent Rank (determined by Pomeroy) on Efficiency:




The scatterplot doesn't look like much, but the trend line is there, and it is significant: Duke's opponents get tougher as the season goes on. And Duke does play much better against inferior competition:


Since Duke's opponents are harder later in the season, and Duke has lower efficiency margins against better opponents, how can we take this into effect? One way is with an Analysis of Variance (ANOVA: more info here), in which we can specify variance components. Basically, we have two main effects on efficiency margin: ACC Game # and Opponent Rank. If we account for the variance accounted for by the strength of the opponent, is the correlation still significant? For the stat-geeks out there, here's the ANOVA table:

Anova Table (Type III tests)

Response: Delta.100
......Sum Sq....... Df........ F value........ Pr(>F)
(Intercept) 0.12776 ....1 ........6.0593 ..........0.015267 *
Opp.Rank 0.48675 ..1...... 23.0858 .........4.563e-06 ***
Game 0.19808 .....1 ........9.3947 ...........0.002693 **
Residuals 2.50903 ....119

To summarize, there is still an overall significant downward trend in efficiency margin as the season progresses, although the significance is reduced.

3) Home Court Matters? When Ken Pomeroy adjusts for home court, he adds 1.4% to the home team's offensive efficiency and visiting team's defensive efficiency, and subtracts the same from the home team's DE and visiting team's OE. So the difference between Faranoff's raw data and what Pomeroy would consider "adjusted" is -2.8 for Duke's home games and +2.8 for Duke's away games. What happens to the correlation if we make the "Pomeroy Adjustment"?



The correlation coefficient decreases, as does the significance, but not to the point where the slope becomes non-significant. There is still a Duke Fade when we account for home and away games.

I must say I come away unimpressed with other explanations for the Duke Fade. Opponents do get tougher but not enough to overcome the efficiency drop. Adjusting for home and away games also doesn't have much of an effect. It is very important to note that nowhere have I suggested a causal agent for the Duke Fade. This is to avoid the common fallacy that correlation implies causation. Clearly, Duke can still have an historic season (2004) despite having one of the few significant in-year Duke Fades.

Instead, I'll take an "I Report, You Decide" kind of approach here. These are the statistical facts, and I'll be happy to attempt more rigorous investigations if they are suggested in the comments.

Worst Duke Defensive Performances

It's been a while since we've done college basketball here, and I have a few things planned for the coming months, including a systematic re-do of last year's tournament simulation. In the meantime, I want to nip any "Matt's a Duke fanboy" criticism in the proverbial bud by doing a negative post about Duke.

The tempo-free era of college basketball began with the 2003-2004 season as Ken Pomeroy started putting posting his rankings based on offensive and defensive efficiency. Duke, for whatever reason, has always done pretty well during the regular season in Pomeroy's adjusted (for opponent offensive and defensive strength) rankings:

Year/Offensive Efficiency/ Defensive Efficiency
2010/1/18
2009/10/20
2008/11/9
2007/40/5
2006/5/13
2005/15/1
2004/2/4

Nevertheless, Duke has put up some hard-to-believe individual games on both sides of the ball. Defense, however, is so intricately tied to Coach K's philosophy that it is the better choice for a comprehensive breakdown. Defensive ability puts players on the floor for Coach K, and can limit the minutes of potentially explosive offensive perimeter players, if they cannot grasp Duke's defensive philosophy (c.f. Taylor King, Elliot Williams, Andre Dawkins). Usually, the result is a solid defensive gameplan that has consistently been in the top 20 the past six and a half seasons.

There have been great defensive efforts, and not always against inferior competition. In fact, the best defensive performance of the 228 games recorded on kenpom.com is this one, played December 19, 2009 against Gonzaga in Madison Square Garden. Duke held the Zags to an efficiency of 57.1, which is absolutely stellar when you consider that Gonzaga's 2009-2010 average is 111.3! But it has not been all good news for Duke this year, and it is an historic defensive lapse that is the reason for this post. Here are the top 10 worst defensive performances since 2003-2004:

#10 (118.4): January 14 2006 at Clemson (Duke W 87-77). We start with a surprising performance in that not only is it a Duke win, but also a win on the road. Although the 2005-2006 Duke team was frequently spotlighted for it's excellent defense, led by Shelden Williams' shotblocking ability, on this night at Littlejohn, things did not go well. Giving up more than a point per possession to a Clemson team that did not make the NCAA tournament and finished 94th in the nation in adjusted defense was simply not acceptable. Duke had some other defensive clunkers along the way, but eventually fell in the NCAA tournament due to their worst offensive performance in the tempo-free era. (But as Alton Brown might say, that's another post...)

#9 (119.0) November 16 2008 vs Rhode Island (Duke W 82-79). This was the night that RIU's Jimmy Barron almost got a permanent middle name from Duke fans. Barron hit seven straight three-pointers before Dave McClure came off the bench to get a hand in Barron's face, causing him to heave an air-ball with 1:24 remaining and Duke down by 2 (ESPN's play-by-play calls the shot a 2-pointer, but I was at the game and remember differently). This was by far the loudest I've heard Cameron in a non-conference game. I also had the pleasure of high-fiving Jimmy Barron as he ran off the court, and I have not washed that hand since.

#8 (119.1) March 8 2009 at North Carolina (Duke L 79-71). This was the closer of the two Duke-UNC games last year, and both teams were had worse efficiencies than the earlier matchup. The pace was 13 possessions slower as well. The biggest standout is that the Tar Heels rebounded over 40% of their missed shots, while Duke's offensive rebounding percentage was a dismal 18.8%. Eww.

#6t (121.3) February 18 2004 at Wake Forest (Duke L 90-84). Duke's best team during the Tempo-Free era only lost six games all season, and every time they did, they allowed more than a point per possession. It was Duke's second loss in a week (they lost at NC State earlier) and is perhaps the best lesson for Chicken-Little Duke fans and Duke haters alike, concerning this year's Duke team. Despite the efforts of the media and the common fan, "consistency" just doesn't mean anything. Especially in ACC road games. A team can put up clunkers in consecutive games in January and still get within an Okafor of the national championship game.

#6t (121.3) January 21 2006 at Georgetown (Duke L 87-84). From the second paragraph of that ESPN recap: "That's my child," the elder Thompson said. "I love my child. After all he's had to go through, he deserves this." Duke never led in a classic execution of the Princeton offense, and JJ Redick scored 41 points, and with Duke almost matching the Hoyas' offensive efficiency with a 117.3 rating. Free throws were the difference, as Georgetown got to the line more often than Duke. It is unclear what the elder Thompson said of Duke's destruction of Georgetown in 2009.

#5 (124.5) February 22 2009 vs Wake Forest (Duke W 101-91). Last year was Duke's worst from a defensive standpoint, and it shows in this top ten list. This game was the polar opposite of the game a few weeks earlier in Winston-Salem, a two point loss for Duke in which neither team topped 95 in efficiency. The rematch in Cameron however had a similar number of possessions and basically no defense.

#4 (125.8) February 20 2005 vs Wake Forest (Duke W 102-92). An eerily similar game to the one above, although this rematch played out exactly like the preceding game at Wake Forest (see below); the only difference was the result for Duke. Interesting point about the 2004-2005 Duke team; if you check here, you can see all the factors that were correlated to Duke's defensive performance that year. Interestingly, nearly all the factors are in bold, indicating a significant (at the 95% confidence level) correlation. Duke's defensive performance that year was strongly tied to their opponents' shooting, rebounding ability, turnover rate, and ability to get to the free throw line. Defense was also significantly correlated to Duke's own offensive ability that night, especially on Duke's offensive glass. It should come as no surprise, then, that Duke was knocked off in the Sweet 16 in a game to a Michigan State team that was among the best in offensive rebounding, among other things.

#3 (127.0) January 19, 2010 at NC State (Duke L 88-74). Ah, the inspiration for this post. Duke was outplayed on their defensive end in a big way, and NC State was helped by a healthy 62.7 effective field goal percentage. They also protected the ball, turning it over on just 13% of their possessions, and turnover rate seems to be a relative strength of this year's Wolfpack team. Offensive efficiency, however, has not exactly been consistent for NC State, and while they put up similar numbers against Georgia Southern and UNC-G, an effort like this against a top-20 defense was completely unexpected. I see no reason to see the game as anything other than a fluke for Duke, and while winning at Littlejohn tomorrow will be a tough task, if Duke loses it will not be due to another defensive calamity. For this, in K, I trust.

#2 (127.6) February 11 2009 vs North Carolina (Duke L 102-87). Easily the worst Duke game I have ever attended, as Duke was never really in this game. Unlike some of the other games, this was not a defensive lapse against an otherwise mediocre offense. This was a lashing at the hands of the eventual champs who could not stop two All-Americans from doing whatever they want on the court. Yes, I'm a little bitter that I slept outside in a tent to watch this game. Next.

#1 (131.6) February 2 2005 at Wake Forest (Duke L 92-89). So many surprising things about this list, including the number of home games (4) and the number of Duke wins (4) and the number of appearances by the Demon Deacons (4). There is quite a wide gap between #2 and this game, and Duke almost pulled off the win! This was a collision of elite squads, as Duke finished the 04-05 season with the best defense in the nation, while Chris Paul's team was the #2 offense. Wake's inability to stop anyone came back to bite them in March, as they couldn't shoot their way out of early exits in both the ACC and NCAA tournaments.

To be fair, Wake Forest dominated the the middle 36 minutes of the game and it was only the 3-point abilities of the talented Mr. Redick that brought the game close at the end: JJ hit three from beyond the arc and Sean Dockery made it 90-89 with two seconds left. Taron Downey hit both of his free throws and Redick missed a running three to end the game. Notably, Duke's offensive efficiency in this game was 127.3, and so one must conclude that it was indeed Duke's defense that prevented the win. As the rematch (see #4) showed, home court has a lot to do with the outcome of games like these.

The biggest absence from this top 10 list: games in March. For all of the hate heaped upon Duke for its struggles in the month of March, not once did they make an NCAA tournament exit due to a sudden lack of defense. In fact, the worst NCAA tournament performance is (predictably) the 2007 first-round loss to VCU, which is 27th on the list at 112.0, followed by last year's win over Texas (36th at 109.3). But those games are miles from the ones above, and allowing around 110 points/100 possessions is probably to be expected from some of the elite offenses in the nation. Coach K gets his teams prepared on the defensive end for March, combined with playing non-ACC teams unfamiliar with Duke's defensive style. There are relatively more games in ACC tournament on the list.

I have compiled the stats from kenpom.com from all years into one spreadsheet, which can be found here for your sorting pleasure. Tempo-free stats can tell us a lot about a team that we weren't expecting to hear. This would be not-so-subtle foreshadowing of a future post about Duke. For a further hint, see this and this.