Jake Peavy’s first start of the 2010 season was if anything to me, concerning.

No, I am not calling for Peavy’s head, wishing the White Sox did not acquire him, or anything of that nature. I was just concerned with the way the start went.

Jake Peavy

In actuality, Tuesday’s start itself was not poor (5 IP, 7 H, 3 ER, 5 Ks, 44 Game Score, 104 pitches). Of course, it is not what White Sox fans want out from the 29-year-old, but overall the start was far from terrible.

The problem to me was Peavy’s “stuff.” He did not seem to be missing many bats and his velocity seemed well below what I was used to seeing in my limited viewing of Peavy’s starts.

Luckily, using Pitchf/X data (credit: BrooksBaseball.net ), we can analyze Peavy’s start in detail. What the data really bears out is, unfortunately, my concern. The Peavy we saw Tuesday did not have typical Peavy “stuff.”

For comparison, I called up Peavy’s September 25, 2009 start against the Detroit Tigers at U.S. Cellular Field. While it was not his best start as a member of the White Sox in 2009, it was, however, his most successful at U.S. Cellular Field.

So now, let us get down to the numbers. There are a few glaring areas of concern: fastball velocity, vertical break on four-seam fastballs, curveballs, and sliders, and lastly, horizontal break on his cutter, curveball, and changeup.

September 25th of last year, Jake Peavy’s velocity on four-seam fastballs averaged out at around 91.64 mph. Tuesday, he was at around 90.77 mph. While not a huge drop off, it’s enough to make a difference at the major league level.

In terms of horizontal break, Peavy was decidedly far more effective in late September than he was Tuesday.

His four-seam fastball’s break was -7.30 in September, -6.51 Tuesday, .79 inches less. The slider went from 3.28 in September to 2.50 and his curveball 5.04 all the way down to 3.84. Peavy was simply not moving the ball inside and outside with the same effectiveness that he did six months ago.

Vertical break is where the numbers truly begin to get concerning.

Peavy’s changeup had 8.13 inches of vertical break back in September, Tuesday that number had shrunk all the way to 4.13. This four-inch decrease should be taken with a slight grain of salt, as Peavy only threw his changeup once in September and a mere five times Tuesday.

His curveball, which he threw six times Tuesday was reduced from -3.65 to -2.45 and his cutter, which he threw 17 times compared with just five in September, fell in vertical break from 7.23 to 5.85.

What does it all mean? There is really no way to tell just yet. Obviously, this was his first start, his home opening of 2010, in less than stellar, rainy, and cold weather. This is an extremely small sample size to go off.

A few positives to take from Tuesday though, Peavy did not throw his slider quite as much as he did in last year’s start (27 vs. 14). The slider was arguably his most dangerous pitch during the earlier start as seven of his 10 swinging strikes were with the slider.

This discrepancy showed as well Tuesday, as Peavy only had four swinging strikes, two of which coming on his cutter.

All and all, do not worry Sox fans.

There are still 160 games left in the season and plenty of future Peavy starts. I will, however, say you should not be afraid to be concerned or a little disappointed with what you saw Tuesday. You have good reason to be.

Simply, if the White Sox are to compete for the AL Central, they will need a lot more of the September 25 Peavy and far less of his April 7 incarnation.

As always, don’t forget to check out 643 Sports LIVE Mondays at 7pm CST/8pm EST at http://www.blogtalkradio.com/643sports

-Rich Kraetsch

Leave a Comment

Your email address will not be published. Required fields are marked *