The White Sox's best curveball

Wednesday was a day to get me thinking about curveballs. The White Sox signed Javy Guerra who has a curveball. Some quick investigation made me realize that dropping his curveball might be a quick Coop fix. During the game with the Reds, Steve Stone told a story about a time when he met with Mel Stottlemyre while still an amateur and talked about curveballs with him. That got me thinking about who on the Sox has the best curveball right now.

The curveball is somewhat of a rarity for the projected members of the White Sox pitching corps. The emphasis on cutters, sliders, and sinkers have left the curveball a bit neglected. The primary users of curveballs for the Sox going into the season are Donnie Veal, Jose Quintana, John Danks, Scott Downs, and Erik Johnson. Not surprisingly, four of the five started their baseball careers with other major league organizations.

Of the bunch, Donnie Veal is far and away a curveball pitcher. Last season, almost 40% of his pitches were curveballs. Most importantly, it's a good one. Just ask Prince Fielder.

Whiffs and fouls

The table above, using data from Brooks Baseball, shows the Pitch IQ values for whiffs and fouls per swing for Donnie Veal's curveball from the 2013 season. The Pitch IQ score is similar to OPS+ so a score greater than 100 is higher than average while a score less than 100 is less than average.

At 146, Donnie Veal has certainly been a genius at getting whiffs on his curveball. That amounts to a whiff 55.74% of the time hitters swung at his curveball. Another 18.03% of the time, they fouled it off.

Balls in Play

When hitters actually got some wood on the ball, they were able to do some damage. Veal did give up significantly more line drives than the average curveballer, which often lead to solid base hits. His home run percentage for balls in play was also about average. Fortunately, getting a Donnie Veal curveball into play is much easier said than done. The batting average against his curveball was .095.

The Results

In FanGraphs has a statistic called "Curveball runs above average per 100 pitches" or wCB/C that can be used to compare the effectiveness of curveballs between pitchers. Veal's 1.55 was the highest for the regular curveball pitchers for the White Sox last year, and he was also in the top 10 for all relievers with more than 20 innings. Overall, Fangraphs had his curveball worth 3.1 runs for the season above the average pitcher. That was good for a 2.2 run lead over Andre Rienzo's curveball.

While Donnie Veal isn't expected to pitch a huge number of innings as a LOOGY, his curveball is a big key to his success. On its own, it was worth 0.3 fWAR for the White Sox last year in only 29⅓ innings. If he can keep up this level of effectiveness with his curveball, he has a good chance to beat the projections for his 2014 season.