Chris Carpenter: Too Diminished to Start?

Chris Carpenter did not have a good game on Monday. He only struck out one batter in four innings, and though he only allowed two earned runs in his four innings, he did surrender eight baserunners and five runs in the loss that evened the National League Championship Series. By the time it was done, the announcers had his fastball diving three-plus miles per hour off its normal pace, and the twittersphere was contemplating which delicious young prospect should come out of the St. Louis pen to start over Carpenter the next time he was due on the hill.

Maybe the eulogies came a little early?

For one, Carpenter wasn’t so far off his peak fastball velocity this season. He hit 92 mph consistently through the game and average just under 91 mph for the night. He sat 92.4 mph last year on his sinker. And even if that’s a drop worth talking about — even a predictive drop at this point, considering what Jeff Zimmerman found about fastball velocities of pitchers returning from the disabled list — it’s probably not as dire as some had it.

The difference between 91 and 92+ doesn’t portend doom by itself. Despite Mike Fast’s older study that found that losing a mile per hour of velocity equates to adding about .25 runs allowed to a pitchers’ ledger, Thomas Karakolis found that fastball velocities between 90 and 94 all pretty much allowed the same ratio of swinging strikes to home runs. At first you might wonder why we watch the gun so hard if this is true, but the sniff test ultimately reveals the old-timey truth in Karakolis’ community blog findings: we don’t talk about a pitcher’s fastball in hushed tones until it regulars lights up numbers higher than 95 on the gun.

And anyway, if the bite is there on his other pitches, add .25 runs allowed to Chris Carpenter and you still have a pretty good pitcher. Dude’s pitched to a low-threes FIP in his last 600 innings, after all. But were his other pitches the same?

Let’s look back a calendar year at Carpenter’s start against the Brewers. It wasn’t his best in the 2011 postseason — five innings, three runs, three strikeouts, three walks and six hits — but there was something different about it. According to Brooks Baseball, Carpenter’s curveball got two-plus inches more drop in that start than it did Monday. That curveball got two whiffs in 21 pitches, yesterday he got zero whiffs in 15 tries. In the regular season last year, Carp’s yakker got 11.2% whiffs (731 n). This year in the regular season, it got 2.7% whiffs (37 n). There could be something wrong with his vaunted Uncle Charlie.

On September 23rd, 2011, Carpenter held the Cubs to one run in seven innings with five strikeouts and two walks. He threw 16 curveballs with an average vertical drop over 11 inches. He got two swinging strikes. Here’s one:

On October 2nd, 2012, Carpenter held the Reds to three runs in six innings with seven strikeouts and two walks. He threw 15 curveballs with an average vertical drop over about eight inches. He got no swinging strikes. Here’s one of his curveballs that day, which came right after another curve that looked just about the same:

A couple swinging strikes here or there might not seem like a big deal. A mile per hour (plus) lost on the fastball might also not be a big deal. But those two curveballs do not look alike, and if Carpenter is missing that pitch, he’s suddenly a 91 mph sinker, 87 mph cutter, and get-em-over curve guy. If you can ignore the curve (it’s always been his worst pitch at finding the zone, around 40% over his career), then you can zero in on one speed. Now he’s got more of a two-pitch repertoire, and that’s what usually makes a pitcher a reliever.

Chris Carpenter may be gutting one out for the team so soon after major surgery, but if he’s currently got a reliever’s arsenal, perhaps his manager should treat him as one and have a quick hook for his veteran if he starts him again. Watching the curve could help Mike Matheny get out in front of a blowup later this series.