Curveball Key for Shields vs. Yankees

James Shields needs to live up to his "Big Game" billing tonight, as the Rays (one game behind Boston in the Wild Card standings) open a three-game set with the Yankees. Shields has shut down New York this year, posting a 27/7 K/BB ratio in 30 innings pitched while holding Bombers batters to a collective .222/.270/.343 line. A big reason for Shields' success against the majors' second-most potent offense is that he's using his curveball, a pitch that makes some Yankees look Cerrano-like, more often.

Shields has increased his curveball usage from 13 percent in 2010 to 21 percent this year. The bender,  dropping a couple more inches compared to last season, is holding hitters to a .199 Weighted On-Base Average (wOBA), well below the .253 league average. The Yankees, meanwhile, haven't hit curveballs well this season. It's the only pitch against which the club has a below-average team wOBA:

2011 Yankees Team wOBA by Pitch Type (league average in parentheses)

Fastball: .382 (.340)

Sinker: .345 (.343)

Cutter: .323 (.311)

Slider: .302 (.263)

Changeup: .299 (.290)

Splitter: .289 (.279)

Curveball: .248 (.253)

Here are the Yankee hitters who are scuffling against curveballs in 2011:

Brett Gardner, .117

Mark Teixeira, .190

Nick Swisher, .239

Curtis Granderson, .251

Alex Rodriguez, .256

Rodriguez (.344 wOBA vs. curves from 2008-2011) typically crushes curveballs, but that hasn't been the case this season. Gardner (.216), Teixeira (.263), Swisher (.226) and Granderson (.241) have long been jelly-legged against curves.  

Shields has tossed his curveball for a strike nearly 70 percent of the time against the Yankees, giving up just one extra-base hit in the process. Look for the pitch to play a prominent role tonight as Tampa continues its late-season playoff pursuit.