As Sox fans will remember, it was clear in 2003 that Pedro Martinez wasn’t the same pitcher after he had reached a pitch count of 100. This was explored deeply in Mind Game by the Baseball Prospectus authors and you shouldn’t need me to remind you that ignoring this pattern led to the Sox’ downfall that year.

In 2011, we’re seeing a similar phenomenon with a member of the Red Sox rotation, Tim Wakefield, only he’s not getting to pitch 100. Take a look at these splits after the jump:

It’s pretty clear from these splits that once Wakefield gets to around pitch 80 or so, he starts to fall apart. We’ve seen this in his last two starts: On July 24 against the Mariners’ historically bad offense, he had thrown 84 pitches and allowed 3 runs entering the 7th inning. With no one warming, he allowed a deep drive to center that was caught, then three consecutive line drives for singles followed by a Brendan Ryan grand slam.

The Sox were ahead 11-3 to begin the inning, so I defended Francona on Twitter by speculating that Wake would have been taken out earlier had the game been close. In his next start yesterday, though, Wake had been pitching a gem through 6, allowing just 3 baserunners through 83 pitches. Though the game was close, Francona had no one warming, and Wakefield walked Quentin and gave up a bomb to AJ Pierzynski. He got out of the inning without further damage, but the Sox couldn’t score and the game was lost.

The treatment of pitchers has come a long way in the last decade or two, and pitchers are no longer allowed to throw 150 pitches and abuse their arms. 100 pitches has become the new rule of thumb, as most starters are taken out around that point, unless they are Roy Halladay, or pitching very well, or managed by Dusty Baker. But it seems from the data we have on Wakefield that he’s not able to go 100 pitches, and in fact loses effectiveness at around pitch 80 or so.

What modern pitching usage has done is divide pitchers into two distinct categories: starters and relievers. The former is expected to be able to go 100 pitches every 5 days, while the latter is expected to be able to throw 20-40 pitches more frequently. But what the data shows us is that perhaps in the case of 44-year-old pitchers with pot-bellies (and probably elsewhere too), there are guys who can only go 80 pitches or so before they lose effectiveness. Maybe Wakefield could go 75 pitches every 4 days, but the Sox are not in a position to try that. But with Aceves’s seemingly rubber arm, a strong pen otherwise, and two workhorses at the top of the rotation, it shouldn’t be a big problem to limit Wakefield to 80 or so pitches, especially if that routinely means 6 effective innings. Unfortunately, I’m not sure Francona, Curt Young and the Red Sox coaching staff realizes this (or perhaps Wakefield himself).