Wednesday, July 30, 2008

Mariano Rivera: Greatest Pitcher of All Time

In a mop-up role, having not pitched for four days, Mariano Rivera took the mound in the ninth inning, facing the heart of the Baltimore Orioles' lineup. It started poorly, as Aubry Huff knocked Rivera's fourth cutter into the right field seats. But Mo settled down to retire Melvin Mora, Jay Payton, and Kevin Millar in order, vaulting himself into the history books.

That one inning pitched last night in Baltimore gives Mariano Rivera 1000.33 innings pitched for his career. By reaching this plateau, Rivera now qualifies for the all-time ERA and ERA+ leaderboards, according to Baseball-Reference.com. First, the classic statistic-- earned run average. Rivera now ranks 17th all time, tied with Jim Scott. Four of the pitchers ahead of Rivera had their careers end before 1900; the latest anyone ahead of him pitched was 1933 (some guy named Ruth), pitched seriously- 1927 (Walter Johnson).

If there's one thing the statistics revolution has taught me, it's that athletes are best judged relative to their peers. For while raw statistics are impressive, their true meaning only comes from studying how much better a great athlete was, compared to his competition. And so we reveal the new career adjusted ERA+ leader: Mariano Rivera. According to ERA+, Rivera has, since 1995, been 98 percent better than his peers, measured by ability to prevent earned runs. Rivera not only takes the top spot; he dominates it. Which raises the question: is Mariano Rivera the greatest pitcher of all time?

Clearly, mlb.com does not think a reliever should enter the discussion. Officially, to qualify for the career ERA title, one has to pitch 2000 innings, double the amount required by baseball-reference. A starting pitcher probably could eclipse the lower mark (1000 innings) in four or five full seasons; indeed Jake Peavy (7 seasons, 1202 IP) and Brandon Webb (6 seasons- 1235 IP) already grace the Active ERA leaderboard. But none of them have an ERA+ anywhere near the range of Mariano Rivera. Is his elevated ERA+ a factor of being a relief pitcher?

The short answer is: perhaps. Goose Gossage, whose recent election to the Hall of Fame might finally open the door for closers, finished with 1809 IP and an ERA+ of 126. All-Time saves leader Trevor Hoffman, who will soon match the 1000 IP plateau, has a career ERA+ of 144. Rather than try and name everyone; here is a list of all pitchers who relieved at least 80% of their games and threw at least 750 innings. Even with a lowered standard, only one other pitcher eclipses Pedro Martinez's record for career ERA+ by a starter (157)- Billy Wagner at 181. Rivera well out-paces Wagner's 181, although it lends some credence to the theory that relievers have inflated ERA+ that shouldn't be quantitatively compared to that of a lifetime starter.

Still, one has to expand the field to include all pitchers with 200 IP to find a single player who eclipses Rivera's ERA+ mark (and I didn't like who I found there either). Whatever the adjustment made to Rivera's numbers, due to his pitching role, it cannot completely erase how Rivera's peers have failed to come anywhere close to his production. Among pitchers with 1000 IP, Rivera is also in the top 25 in Strikeouts 9/IP, all time. Since 1995, no pitcher has prevented home runs better than Rivera. For fourteen seasons, Rivera has compiled a resume that I believe allows him to be compared with the starting pitchers, and statistically he rises as the best. And of course Rivera is, without a doubt the greatest relief pitcher of all time.

But if we can define "greatness" by performance relative to one's peers, no pitcher is greater than Mariano Rivera.

Who cares to challenge this?

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3 comments:

JL25and3 said...

OK, I'll bite. I can make a counter-argument, or at least dispute the grounds of this one.

I wouldn't dream of disparaging Mariano's achievement in any way. He's come about as close to perfection as possible - but it's also extremely limited. No one else can do what Mariano does, and certainly not with his long-term consistency; at the same time, he's incapable of doing what every moderately successful starter does. And there definitely comes a point where 150-200 IP of grade A pitching means more - and is even a greater accomplishment - than 75 innings of A+.

A great hitter is a great hitter regardless of context, but Mariano is only a great pitcher in a very specific context - and someone else has to pitch 8 innings to get him there.

All of that makes it pretty hard for me to call him The Greatest Pitcher. In fact, I don't you can compare him with Pedro at all. We call them both "pitchers," but in fact what they do is really quite different, and I don't think they can be measured on the same scale. The category of "Greatest Pitcher" really doesn't exist anymore; it has to be two categories, because it's two very different jobs.

So call Mariano The Greatest Relief Pitcher. I don't think it's valid to go beyond that.

Matt said...

You make a good argument about the basis of calling a "greatest pitcher" in the first place. The last 30 years have seen the invention of a new position- and Rivera is the best to have ever played that position.

But one can rank the greatest players of all time at each position and still choose, from among them, the greatest position player of all time. This is because we understand the relative effect of having a great hitter or great fielder at a particular position on the field. First base defense is not as important as first base offense, for example.

So while I agree that it is certainly easier to be a reliever than to be a starter, and that most starters are more valuable than almost all relievers. But still, I have to look at the statistics- for all pitchers who have ever pitched more than 300 innings, Rivera has the best ERA+. For 1000 innings, it's, the best by far. It's that separation that I think makes Rivera the best ever.

Similarly if there were a catcher whose hitting statistics were so much better than other catchers (but not quite the best hitting statistics overall), there would be a good case for that player being the best ever. Rivera's position (reliever) does call for some knockdown, compared to other pitchers. But at some point, the knockdown doesn't make up for the gap between Rivera and the best of the starters. I believe it doesn't.

JL25and3 said...

Good response, that got me thinking more.

Yes, his ERA+ is stupendously the best for all pitchers over 1000 IP. You're right, that makes him the best - but, really, only if you ignore all the innings over 1000. Mariano's ERA+ is 49 points higher than Lefty Grove's - but Grove did it over almost 4000 IP.

So I did a rough and dirty comparison. I used BR's "neutralize stats" feature, so I could compare ERAs directly. I subtracted that from the neutralized average R/G (not really appropriate, but close, and the same for everyone). I'm going to take that as the average runs saved over average, per 9IP, even though it isn't quite. Then I multiplied by career IP/9.

The average R/G for everyone is 4.42. Grove had an ERA of 2.49, so he's 1.93 R/G better than average. He pitched 3940.67 IP; divide by 9 and multiply by that 1.93 and you get 845 neutralized runs saved, over an average pitcher over the course of his career.

Walter Johnson's 5914 IP saved 1380 runs. Greg Maddux has saved 764. Mariano's saved 265.

Brilliant as Mariano has been, no, I don't think it makes up for that massive difference. Even if you want to say the runs are more important, I can't quite justify it.

(Btw, I didn't say beling a reliever was easier, just different. Mariano only needs one pitch, it's true; but his job requires that that one pitch be consistently perfect, which no starter has to do.)