The Other Really Fast Cincinnati Red

No, not Billy Hamilton, though he's certainly fast. I'm talking about pitching fast, specifically Aroldis Chapman, possessor of the fastest fastball in the majors. So far this year, in 18.1 innings he's allowed just 11 base runners (6 hits, 5 walks), compiling a 0.98 ERA while converting 12 of 13 save opportunities. Most ridiculously,  he's struck out 37 batters, or 56.9% of the batters he's faced.

Here's a list of pitchers who've struck out 40% or more of the batters they've faced in a season of 50 or more innings pitched. As you can see, it's happened only eleven times. And while I couldn't get the sort to work quite right (the percentage of batters struck out is K%), you can see that Chapman's strikeout rate is unprecedented. 

Player	K%	SO	IP	Year	Tm	G	GF	W	L	SV	H	ER	BB	ERA
Craig Kimbrel	50.2%	116	62.2	2012	ATL	63	56	3	1	42	27	7	14	1.01
Kenley Jansen	44.0%	96	53.2	2011	LAD	51	13	2	1	5	30	17	26	2.85
Carlos Marmol	41.6%	138	77.2	2010	CHC	77	70	2	3	38	40	22	52	2.55
Aroldis Chapman	43.4%	112	63.2	2013	CIN	68	55	4	5	38	37	18	29	2.54
Aroldis Chapman	44.2%	122	71.2	2012	CIN	68	52	5	5	38	35	12	23	1.51
Eric Gagne	44.8%	137	82.1	2003	LAD	77	67	2	3	55	37	11	20	1.20
Billy Wagner	43.4%	124	74.2	1999	HOU	66	55	4	1	39	35	13	23	1.57
Brad Lidge	42.5%	157	94.2	2004	HOU	80	44	6	5	29	57	20	30	1.90
Craig Kimbrel	41.5%	127	77.0	2011	ATL	79	64	4	3	46	48	18	32	2.10
Armando Benitez	41.0%	128	78.0	1999	NYM	77	42	4	3	22	40	16	41	1.85
Greg Holland	40.4%	103	67.0	2013	KCR	68	61	2	1	47	40	9	18	1.21

Provided by Baseball-Reference.com: View Play Index Tool Used

Generated 6/20/2014.

Chapman's season started late because he was hit in the face by a line drive at the end of March,  necessitating surgery to repair bones around his left eye and nose. There were questions about how he'd recover psychologically. I'd say he's OK.