Jack Moore of Fangraphs posted about Craig Kimbrel earlier today, saying that Kimbrel is his "most anticipated reliever of the year" for 2011. I haven't formulated a list of candidates, but if I did, I might wind up agreeing with Jack. Kimbrel was absolutely filthy in his 2010 cameo, which spanned 20 2/3 innings in 21 games. He struck out 40 hitters, which is a Marmolian 17.42 per nine. The walk rate, at just under 7 per 9, is ugly, but it's not a concern if he can strike out hitters with such frequency. His xFIP of 2.54 was significantly higher than his ERA (0.44) and FIP (1.53), but still was better than all but 5 pitchers (minimum 20 innings) in that category: Stephen Strasburg (2.15), Rafael Betancourt (2.29), 2010 teammate Billy Wagner (2.34), and Joe Thatcher (2.36) bested him last year. Kimbrel's whiff rate of .370 last year was absurd; only Carlos Marmol was better.
Last year, Kimbrel showed two pitches: a fastball and a slider. The fastball averages 95-96 with good riding action, and the slider sits in the mid 80s with a ton of topspin. Hitters missed on exactly one-third of swings against the fastball, which is better than twice the league average for four-seamers. On the slider, the whiff rate was .516, which would be one of the best in the league over a whole season. Both pitches faired very well in both versions of run values that I use, RV/100 (based on actual outcomes) and xRV/100 (based on batted ball profile):
FF: -1.14 RV/100, -0.91 xRV/100
SL: -4.99 RV/100, -3.80 xRV/100
Two things to conclude with: in addition to the control issues I mentioned before, Kimbrel has trouble getting groundballs. PITCHf/x data has his groundball rate at .233, which is the among the lowest rates in the league. That includes an extremely low .130 mark on the 23 fastballs put in play. The other thing is that we need to remember that we're dealing with a ridiculously small sample. Still, that doesn't mean we can't get excited, right?