A lot of Gavin Floyd's success is tied to his curveball, but he threw it much less in 2010 than previous years.
In a 2004 scouting report, Floyd's curveball was described as "one of the best breaking pitches in the minor leagues." From 2008-2010, that description materialized into Floyd having the sixth-best curveball in baseball since he cemented his place in the White Sox rotation.
But oddly, Floyd threw fewer curveballs in 2010—and had a fine season. After 18 percent of his pitches in 2008 and 2009 were curveballs, he threw curves on just 15 percent of his pitches in 2010. His FIP last season was a career-best 3.46, as compared to 3.77 in 2009 and 4.77 in 2008. Floyd's 4.3 WAR shouldn't be read as worse than his 2009 WAR of 4.6—remember, WAR is more of a blunt hammer than precise chisel.
Trying to decipher why Floyd threw fewer curveballs is the real question, though. Luckily, FanGraphs provides heat maps that offer us a clue:
Images via FanGraphs
Floyd likes to stay away from lefties and righties with his curveball—not an earth-shattering conclusion—but he missed a lot over the plate with his curveball in 2010. Compare that to his 2009 curveball heat maps, and it makes sense why he threw it less last season:
All those pitches on the middle and inner third of the plate explain why Floyd's curveball was less effective in 2010 (0.85 w/RC to 2.69 w/RC in '09) and why, in turn, he threw it less. In turn, Floyd threw his cutter with greater effectiveness, leading to the level of success he enjoyed last season.
What's encouraging is that Floyd hasn't just lost the ability to throw his curveball at an elite level. His success with the curveball is tied to his command of it—and even when he doesn't have pinpoint command (like 2010) it's still an effective pitch.
So maybe that opening sentence should read differently: Gavin Floyd's curveball is the pitch that could separate him from being a very good pitcher and a potentially-elite pitcher. If Floyd can throw his curveball like it's 2009 and still command his cutter, fastball, slider and changeup as well as he did in 2010, he could turn in a season worthy of ace status.