Grant Balfour’s Fastball

Grant Balfour might be the only baseball player around who participates in triathlons competition during the off-season. He’s not, however, the only baseball player to have an issue with walking batters while featuring a fastball so hot it produces solar flares. Something peculiar has happened so far this season, though. Balfour’s strikeout-to-walk ratio is sitting over six, a drastic improvement compared to a previous career rate a little over 2.2. Meanwhile Balfour’s fastball velocity has dipped about a mile per hour.

Announcers often talk about improving control by decreasing velocity. Whether this is a conscious change in Balfour’s game or not is anyone’s guess. The results are pretty glaring though. The top 16% of Balfour’s fastballs are averaging about 94 miles per hour (as opposed to 95 and 96 MPH in 2009 and 2008) while the bottom 16% are also about a mile per hour lower than in the past. The full table of these figures is posted below, and suggests that Balfour’s velocity has dropped by an equal rate at each level for two years running. Of course there’s a chance this is simply a pitchfx mistake.

Year	N	T16%	M68%	B16%
2010	180	93.9	92.2	90.5
2009	990	95.4	93.3	91.1
2008	920	96.4	94.8	92.9

Undeterred by that possibility, here are the overall results breakdowns for Balfour’s fastballs:

 
Year	N	Cld Sw Str	Foul	Ball
2010	180	0.21	0.08	0.23	0.3
2009	990	0.17	0.09	0.24	0.35
2008	920	0.18	0.12	0.24	0.36

Note the figures in the last column. Balfour has made drastic improvements in reducing the amount of pitches he’s thrown that were called balls. Move your eyes towards the left and you’ll see that these additional strikes are not the result of more whiffs or more fouls, but rather an uptick in called strikes.

There’s a degree of luck that goes into called strikes, no doubt – sometimes the hitter is fooled, sometimes the hitter is taking 100%, other times the umpire messes up – and called strikes do not correlate as well to strikeouts as their swinging variety brethren, but right now, the drop in strikeouts is worth the drop in walks. Balfour’s xFIP is a full run lower (3.21) than it was in 2009, his FIP is more than a run lower, and his tERA is even lower than his 2008 mark, which happens to be the year he did his best Mariano Rivera impression. It’s also worth noting that Balfour is throwing a first pitch strike roughly 69% of the time as opposed to a career rate around 54%.

Balfour will be eligible for free agency at season’s end and as such his agent couldn’t plot a better start to his season.