FanGraphs: The best pitch in baseball

Adam Wainwright pitched 233 innings during the 2009 season while posting a 2.63 ERA and a 3.11 FIP and earning himself a fair share of Cy Young Award votes. It would have been perfectly acceptable and understandable if Wainwright’s performance took a step back this season as hitters adjusted and Wainwright’s ERA increased. Yet the 28-year-old hasn’t taken a step back, and so far, he’s actually taking a step forward by pitching well enough in his first seven starts to record an ERA of 2.08 and a FIP of 2.55.

Seemingly the only change in Wainwright’s approach is an increase in the amount of breaking balls used. Earlier this season on TMI, Mark Simon noted how frequently Wainwright was using his curve last year, and he is even more reliant on his breaking stuff this season.

Throughout his career, about half of the pitches Wainwright threw were fastballs. This season he’s throwing his heater less than 42 percent of the time and instead focusing on his always excellent slider and curve. FanGraphs’ linear weights based on pitch type give run values for each offering, and for his career, Wainwright’s curve is worth 45.2 runs above average and his slider 35.3 runs. It's a stark contrast from the minus-7.6 runs his fastball is valued at, or the plus-3.9 run value of his change-up.

Perhaps the most impressive thing about Wainwright’s success is how predictable his usage has become. The only counts in which Wainwright is throwing a fastball more than 50 percent of the time are obvious fastball situations (1-0, 2-0, 3-0, 2-1, 3-1, and 3-2). He’s using his curveball more than 70 percent of the time in 0-2 counts, and nearly 60 percent of the time in 1-2 and 2-2 counts.

When Wainwright gets ahead –- and he usually does –- batters have to know the hammer is on the way, and yet they still can’t hit the thing. Nearly 13 percent of the curves Wainwright has thrown have been swung at and missed and roughly 70 percent have been strikes –- whether it be of the foul, called, or swinging variety. As far as out pitches go, it’s hard to find one that gets the job done as often as Wainwright’s curve, and it’s easy to see why he’s on the path to a career year.

R.J. Anderson is a writer for FanGraphs.