Nova's Super Slider

With a trip to the ALCS up for grabs, Ivan Nova starts for the Yankees tonight. The 24-year-old righty, who was originally signed out of the Dominican Republic for $80,000 in 2004, took four seasons to escape A-ball and was briefly lost to the Padres in the 2008 Rule V Draft, played a crucial role in New York's rotation while racking up nearly three Wins Above Replacement.

Nova tinkered with a slider in spring training, but he mainly stuck to his fastball, curveball and changeup early on in the 2011 season. Starting in June, however, Nova began to mix in the sharp, mid-to-upper-80s pitch more frequently. For a guy who was criticized as a prospect for lacking a true "out pitch," Nova's slider is quickly turning into just that.

Depending upon the count, Nova either hits the outer portion of the strike zone or tries to get hitters to lunge at the slider off the plate:

Pitch location of Nova's slider

And opponents have obliged by going after lots of those out-of-zone sliders. Check out hitters' swing rate by pitch location against Nova's slider, compared to the league average:

 Hitters' swing rate by pitch location vs. Nova's slider

 League average swing rate vs. sliders

Batters have chased 40 percent of Nova's sliders out of the zone, well above the 34 percent average. While pitching in "relief" of CC Sabathia in rain-interrupted Game One of the ALDS, Nova struck out Miguel Cabrera, Victor Martinez and Austin Jackson swinging on sliders buried in the dirt:

Location of Nova's Ks with his slider vs. Detroit, 9/30/2011

Overall, Nova's slider has limited hitters to a .188 Weighted On-Base Average (wOBA). Many Tigers have been susceptible to the slider this season, with Delmon Young (.153 wOBA vs. sliders), Ramon Santiago (.196), Jackson (.204), Alex Avila (.235) and Don Kelly (.251) all posting wOBAs way below the .262 league average against the pitch. Expect to see Nova's super slider early and often in Game Five.