There has been a lot of debate about high pitch counts for starters and injury. I thought that it might be useful to step back and look at performance.
Baseball Reference contains information about pitcher performance during the 1-25, 26-50, 51-75, 76-100 and 100+ pitch ranges. I was particularly interested in how starters did during the 76-100 range. Usually if a starter has gone 75 pitches in an outing, it means that he didn't come out of the bullpen with nothing and been trashed in one or two innings. This means that the starter's worst starts are not considered at all. On the other hand, 76-100 pitches is generally not thought to be the point of tiredness. So, I looked at the career line with 76-100 pitches of every starter in the American League who had been in the league at least 5 seasons. Here are the results:
The great ones
Pitcher
PA
Opponent's batting line
Halladay
1328
.271/.320/.388
Maddux
3148
.252/.294/.328
Santana
917
.233/.289/.398
Schilling
2512
.247/.289/.388
Clemens
3525
.224/.289/.341
Mussina
2759
.262/.295/.416
The very good ones
Pitcher
PA
Opponent's batting line
Burnett
1011
.237/.325/.398
Beckett
851
.243/.315/.410
Sabathia
1104
.248/.309/.375
Pettitte
2140
.291/.338/.427
K. Rogers
2364
.282/.340/.443
Buerhle
1476
.281/.322/.444
Lackey
1138
.301/.365/.445
Escobar
1134
.253/.321/.386
Colon
1750
.264/.330/.425
Millwood
1686
.269/.325/.421
Bonderman 756 .267/.333/.426 Haren 687 .256/.305/.435
The rest
Pitcher
PA
Opponent's Batting Line
Byrd
1121
.291/.335/.470
Westbrook
850
.257/.310/.364
Cl. Lee
714
.297/.349/.529
Robertson
621
.261/.337/.446
C. Silva
559
.331/.366/.544
Ponson
1338
.289/.354/.453
Garland
1252
.296/.350/.482
Vazquez
1769
.264/.309/.450
Contreras
745
.250/.324/.409
Meche
969
.278/.352/.467
O. Perez
872
.314/.363/.514
Washburn
1418
.264/.315/.444
Batista
1108
.265/.344/.426
JfWeaver
1512
.285/.336/.445
Padilla
852
.282/.344/.446
Ohka 699 .291/.351/.468 VZambrano 535 .236/.354/.383 Towers 466 .298/.338/.472 Maroth 760 .316/.369/.482 Seo 427 .309/.352/.494 RaOrtiz 1144 .267/.339/.491 HoRamirez 492 .281/.357/.514 Kennedy 730 .304/.372/.521 Loaiza 1668 .302/.353/.462
For comparison purposes, the AL averages over the past 5 years are .270/.336/.428. It is pretty clear why managers want to continue sending out the very best pitchers in the game for more than 75 pitches. They are better than the alternatives. But, for all the others, the average reliever will pitch as well or better. Jason Frasor, for example, has been a better pitcher over his career (1-25 or 1-50 pitches) than A. J. Burnett has been after 75 pitches. And in the case of Carlos Silva, for example, almost any pitcher in the Minnesota pen over the last 5 years has been better.
So, what does this data suggest? To me, it suggests that the governing idea of modern starting pitcher usage , the attempt to get 5 starting pitchers to throw between 90-110 pitches each start, is foolish and inefficient. It is a legacy of a different age in baseball, when a complete game by a starting pitcher was a realistic possibility every outing, and consequently "pitcher wins" actually meant a lot more than they do today. Now, managers try hard to give their starting pitchers the opportunity to "win" the game at the expense of the team's likelihood of actually winning.
There are any number of alternatives- 4 man rotations (with each starter limited to 70-80 pitches), 3 day rotations, 5 day hybrids (with the top 1 or 2 starters scheduled to throw as currently and the others paired off and expected to throw roughly 60 pitches each). To implement any of these alternatives, the shape and usage of the bullpen would have to change too. I would not shed a tear about that.
https://www.battersbox.ca/article.php?story=20070928205111972