Jack Cust: No such thing as a free lunchby Mike Fast
April 30, 2008
Last year Jack Cust hit 26 home runs in 395 at-bats with the Oakland A's, and he put up an impressive .256/.408/.504 batting line despite 164 strikeouts. I recently took a detailed look at Cust's 2007 performance with the aid of pitch-by-pitch data from PITCHf/x.
This year, Jack Cust has made a less than impressive start, batting .169 with only one home run in his first 23 games (through April 28). Did pitchers adjust to Cust? For example, are they further exposing the weakness we saw last year against the curveball and avoiding throwing him fastballs to hit? Or is Cust still hitting the ball hard but running through a patch of bad luck in April? Or maybe he isn't hitting the ball hard at all.
Let's examine the possible explanations, with reference to the data from the previous article. Is Cust seeing a different pitch mix this year than in 2007? Last year pitchers threw Cust 48 percent fastballs and 52 percent off-speed pitches. What about this year?
Pitch Type LHP Pct RHP Pct Fastball 32 49% 121 48% Change-up 2 3% 52 21% Slider 19 29% 23 9% Curveball 7 11% 31 12% Cutter 5 8% 11 4% Splitter 0% 12 5% Total 65 250
It looks like pitchers are using a similar approach in 2008 in terms of pitch types in as they did against Cust in 2007.
So, he's not seeing more breaking balls this year. How is he doing against the various pitch types? We know that last year he killed the fastball from right-handed pitchers. Is he doing that again this year?
LHP Pitch Type Pitches Ball CStrk Foul SwStrk InPlay Avg BABIP SLG HR Runs/pitch Fastball 32 0.41 0.16 0.16 0.13 0.16 0.400 0.400 0.800 0.000 0.013 Changeup 2 0.50 0.50 0.00 0.00 0.00 0.065 Slider 19 0.53 0.32 0.05 0.11 0.00 -0.011 Curveball 7 0.43 0.14 0.00 0.43 0.00 -0.022 Cutter 5 0.40 0.40 0.00 0.00 0.20 0.000 0.000 0.000 0.000 -0.059 Total 65 0.45 0.23 0.09 0.14 0.09 0.333 0.333 0.667 0.000 -0.001 RHP Pitch Type Pitches Ball CStrk Foul SwStrk InPlay Avg BABIP SLG HR Runs/pitch Fastball 121 0.40 0.17 0.16 0.10 0.17 0.350 0.316 0.450 0.050 -0.001 Changeup 52 0.44 0.17 0.08 0.19 0.12 0.167 0.167 0.167 0.000 -0.010 Slider 23 0.52 0.22 0.09 0.13 0.04 0.000 0.000 0.000 0.000 -0.004 Curveball 31 0.52 0.32 0.03 0.10 0.03 0.000 0.000 0.000 0.000 -0.005 Cutter 11 0.64 0.27 0.00 0.00 0.09 1.000 1.000 1.000 0.000 0.073 Splitter 12 0.50 0.00 0.00 0.33 0.17 0.500 0.500 0.500 0.000 0.015 Total 250 0.45 0.19 0.10 0.13 0.12 0.323 0.300 0.387 0.032 0.001
Last year, Jack Cust was 16 runs above average against fastballs from right-handed pitchers in the sample for we had PITCHf/x data (covering about three fourths of the pitches Cust saw in 2007). He hit for a .493 batting average and a 1.000 slugging percentage on the 69 fastballs he put into play off right-handed pitching last year. This year he's merely average against the fastball from right handers and only batting .350 and slugging .450 against it. That's not enough to make up for his somewhat subpar performance against other pitch types.
Let's take a quick look at the pitch location charts for the fastball. These charts are shown from the catcher's perspective.
There's nothing that particularly jumps out at me from these charts as a difference from last year. I won't show the charts for the other pitch types since the sample sizes for most of them are fairly small at this point in the season.
We've observed that Jack Cust is not hitting the fastball with authority like he did last year. Let's take a look at where he is hitting balls in the field of play. Field dimensions on these charts are approximate.
Cust is hitting ground balls to the right side and balls in the air to the opposite field.
In the previous article, we observed that Cust hit more fly balls in his hot streaks and more ground balls and pop-ups during his cold streaks. What is his batted ball mix in April this year?
Streak InPlay Fly Ground Line Pop Apr 2008 39 23% 51% 18% 8% 2007 Hot 134 35% 41% 22% 1% 2007 Cold 103 21% 50% 23% 6%
He's hitting a lot of ground balls and pop-ups this year just like he did during his cold streaks last year. In fact, look at his batted ball charts against the fastball from 2007, split between hot and cold streaks.
His batted ball chart from 2008 looks very much like his batted ball chart for his cold streaks from 2007. He's not pulling the ball except on the ground, and that's a recipe for a lot of outs and not many home runs.
Finally, let's take a look at the pitch location for the balls Cust has put in play in 2008.
There are a lot of ground balls shown there but nothing that particularly indicates that pitchers are pitching Cust differently than last year or that Cust is making outs because he's swinging at pitches that are hard to hit. In fact, his lone home run came off a pitch just off the outside edge of the plate, and several of the pitches over the heart of the plate have turned into grounders.
I'm curious if Cust is doing something different mechanically with his swing during his cold streaks. He's clearly not pulling the ball in the air, and that doesn't seem to be due to changes in the pitches he's seeing. Unfortunately, I'm not a guy who can pick up flaws in mechanics from video, so I'll have to leave that analysis to someone else.
Mike Fast is a Royals fan who enjoys investigating baseball questions using data of many sorts. He is a member of Complete Game Consulting. He welcomes comments via e-mail.