Small sample size?
Rick Peterson, current Mets and former A's pitching coach, is one of the important baseball guys who largely flys under the radar. In 1998, Peterson took over the AL worst A's pitching staff and quickly turned it around. From 1998 to 2003 A's pitchers ranked 9th, 3rd, 3rd, 2nd, 1st, 1st in the AL. Notice any kind of a trend there?

Obviously, a lot of that success is due to the arrival of the big three: Hudson, Mulder, and Zito, but Peterson deserves much of the credit for developing and more importantly keeping young pitchers healthy (are you listening Dusty?). Another important point: in addition to the influx of young talent, Peterson has helped quite a few journeymen and underacheivers put together solid seasons. Guys like Mike Neu, Bobby Taylor, John Halama, Gil Heredia, Tim Worrell, Jason Isringhausen, Jeff Tam, Jim Mecir, Corey Lidle, Eric Hiljus, Aaron Harang, and Chad Bradford have all emerged from obscurity, or had their best seasons under Peterson. I understand, there is at least a little bit of a ballpark effect at work, but there really isn't a whole lot of talent on that list.

Now Peterson is gone to the Mets for the 2004 season. Think its going to have an effect on their pitching staff, which gave up 4.68 runs/game and ranked 10th in the NL last year? Well so far it has. Mets pitchers currently rank 1st in the NL with 3.90 runs/game. What about the Peterson-less A's? Well as already mentioned, the A's ranked 1st in the AL in 2003 with 3.97 runs/game. In 2004, they have already fallen to 5th at 4.97 runs/game. I was skeptical at first, but this is starting to look like too much of a coincidince.

I know it is still real early and the sample sizes are small, but that's almost a run difference for both squads, there has to be some reason. Instead of looking at the pitchers who have come and gone for both teams, lets look at the pitchers who have worked under Peterson, and compare their performance to how they fared without Peterson. Below is a list of the 10 innings leaders for the 2003 A's and 2004 Mets, both under Peterson. I compared those numbers with how they did either last year (Mets) or this year (A's) without Peterson.

         w/Peterson   w/o/Peterson           w/o/Peterson    w/Peterson

A's       ERA     IP    ERA     IP   Mets      ERA     IP    ERA     IP                

Zito     3.30  231.7   6.17   35.0   Glavine  4.52  183.3   1.85   39.0

Hudson   2.70  240.0   3.53   43.3   Traschel 3.78  204.7   3.79   38.0

Lilly    4.34  178.3   4.99   30.7   Leiter   3.99  180.7   1.65   27.3

Mulder   3.13  186.7   4.12   39.3   Seo      3.82  188.3   4.91   25.7

Harden   4.46   74.7   4.37   22.7   Yates    0.00      0   5.40   23.3

Foulke   2.08   86.7   0.53   17.0   Stanton  4.57   45.3   3.68   14.7

Bradford 3.04   77.0   7.71    9.3   Weathers 3.03   87.7   3.68   14.7

Rincon   3.25   55.3   3.68    7.3   Wheeler  3.71   51.0   3.46   13.0

Neu      3.64   42.0   0.00      0   Looper   3.68   80.7   0.00   12.3

Halama   4.22  108.7   2.31   11.7   Moreno   7.88    8.0   4.63   11.7

Totals   3.37 1281.0   4.24  216.3   Totals   3.95 1029.7   3.28  219.7

Overall, ptichers have done significantly better under Peterson. Out of the A's, 5 are doing noticably worse, 2 are doing noticably better, and 2 are doing about the same. Now obviously Zito's numbers are likely to improve. But given all these trends can we be so sure that Mulder and Hudson's will? I think they will, but we'll have to wait to find out.

Out of the Mets, 4 pitchers have noticably improved (not counting Moreno), 1 has gotten worse, and 2 are about the same. Glavine, Leiter, and Looper have been unconcious so far. They'll certainly come back down to earth, but can we even be so sure that they won't pitch like Mulder, Hudson, and Foulke last year? Sample size is certainly an issue, roughly 220 innings is not enough to make a determination, but there is a lot of preliminary evidence suggesting Rick Peterson is having a larger effect on his staff's performance than he is getting credit for. It will be interesting to take a look at this once the whole season is in the book.

If it turns out that by season's end, there is this large of an effect, I think I will take a good look at other highly regarded pitching coaches to see if they measure up to Peterson, guys like Leo Mazzone, Dave Duncan, or Joe Kerrigan.

Note: As I was writing this, four Mets pitchers combined to hold San Francisco to only 1 run in 11 innings, while Harden has given up 4 runs to the Yankees through 5, so you can tack a little more evidence onto those numbers up there.
Curt  ¶ 11:03 PM