Is Ivan Nova lucky or good?
Despite going an impressive 16-4 during his rookie season, Nova’s peripherals have been a major source of skepticism. Because of his low K/9 rate of 5.3 and relatively high WHIP of 1.331 in 2011, many have regarded Nova’s 3.70 ERA, which was approximately 20% better than the park adjusted league average, as a stroke of luck. According to xFIP, a metric that calculates “expected” ERA by normalizing a pitcher’s HR rate, Nova should have allowed 4.16 runs per game, which suggests he could be a candidate for regression in 2012.
Interestingly, in two starts this season, Nova has done two things that normalized fielding independent metrics love: he has struck out a lot of batters and surrendered more homers. In fact, he currently ranks within the top-10 in both categories. As a result, Nova’s xFIP is a sparkling 2.55, which is good for second best in the league behind only Jered Weaver.
2012 xFIP Leaders
|Felix Doubront||Red Sox||0||0||10||5.40||2.81||3.03|
Should the Yankees be pleased by the abundance of strikeouts in Nova’s first two starts, or concerned by the elevated hit and HR totals he has allowed? As usual with Nova, there is no easy answer. If the right hander has really taken a big step toward becoming a strikeout pitcher, it would augur well for the rest of 2012, provided his other peripherals return to being in line with 2010-2011 levels. Of course, if his elevated strikeout totals are just a small sample size blip, while his vulnerability to the long ball persists, the outlook would be negative. At this point, more data is needed before making a guess as to which trend is sustainable, but there is an anecdotal point that might bode well for Nova.
During yesterday’s ESPN telecast, former Red Sox manager Terry Francona mentioned that his hitters noted an improvement in Nova’s breaking ball after he returned from a mid-season demotion to the minor leagues. Because Nova throws two breaking pitches, Francona could have been talking about either the curveball or slider, if not both, but if he was referencing the latter, there is some data to support his point.
Before being sent down to Scranton in early July, Nova had thrown 1,490 pitches in 91 2/3 innings, including 393 curveballs, but no sliders. In the 73 2/3 innings after his return, Nova, threw 118 sliders, or almost 10% of his total pitch count. What’s more, Nova recorded 19 strikeouts on the slider, representing 36% of the 53 he amassed since returning against the Mets on July 30. As a result, the rookie was able to increase his K/9 rate from 4.4 before the demotion to 6.5 after being recalled.
Mix Shift of Ivan Nova’s 2011 Pitch Selection
Was the development of a slider the main reason why Nova experienced a second half spike in his strikeout rate? Well, if you subtract the 19 punch outs he recorded on the slider, his K/9 rate would have been 4.2, or just about the same level compiled before being sent to the minors. Granted, Nova would have had a chance to record a strikeout by throwing another pitch in those 19 two-strike counts, but the symmetry is striking.
So far this year, Nova has thrown 12 sliders, which represents 6.2% of his 194 pitches. Meanwhile, he has recorded four of his 15 strikeouts with the pitch, or about 27% of the total. Albeit in a very small sample, Nova’s slider continues to be a very effective pitch for the right hander. In fact, according to fangraph.com’s PITCHf/x data, the slider has already been worth almost one run saved (wSL), which is equal to the amount recorded last season. Obviously, that doesn’t mean Nova’s K/9 rate of 10-plus is sustainable, but it could suggest that he has the potential to strikeout 1 to 2 more batters per nine innings than his current career totals indicate. If so, Nova just might be a strong candidate to improve upon, instead of regress from, his 2011 rookie campaign.