Sox f/x II: Clay Buchholz

The Red Sox now have one win on the season after their out-slugging of the Yankees earlier today.  Clay Buchholz is next in line for the Sox; he will face Ivan Nova tomorrow at 1 on national TV.  Buchholz had a breakout year in 2010, winning 17 games with the lowest ERA in the league.  He's definitely due for some regression this year, but there are still plenty of things to like about Buchholz.  First, here is a look at how his five pitches move.

	mph	pfx_x	pfx_z
Sinker	93.8	-7.8	+8.1
Fastball	94.1	-5.1	+10.2
Cutter	90.1	+1.3	+5.6
Changeup	81.8	-3.0	+6.1
Curveball	78.4	+5.8	-9.2

The above data are from 2010 road games only; Fenway was reporting high mph and pfx_z values for most of the year.  Buchholz's primary fastball is a two-seamer; it doesn't sink a whole lot and is often hard to separate from his four-seamer.  He started throwing a cutter last year after throwing a slider at the beginning of his career.  I wrote about Buchholz's cutter and slider for Beyond the Boxscore last month, if you're interested in more information on this topic.  Buchholz also throws a slow straight changeup (note how much less "run" it has than his fastball) and a 12-6 curveball that gets some of the best downward "drop" in the game (it's similar to the curves of Gio Gonzalez, Kerry Wood, and Matt Garza).  Here's how Buchholz's pitches fared in various measures of effectiveness:

	#	%	RHB%	LHB%	Swing	Whiff	Zone	Chase	Watch	Ball	RV/100	xRV/100
Sinker	900	.322	.317	.327	.464	.105	.406	.327	.334	.368	-0.97	+0.44
Fastball	581	.208	.212	.204	.425	.126	.499	.285	.434	.349	-1.73	+0.30
Cutter	552	.198	.176	.216	.505	.219	.429	.330	.262	.388	-1.32	-1.20
Changeup	523	.187	.197	.179	.501	.462	.424	.316	.248	.373	-1.44	-0.70
Curveball	238	.085	.097	.075	.315	.267	.387	.387	.511	.517	+1.62	+0.29
	2802				.459	.215	.431	.308	.341	.382	-1.12	-0.13

	GB Rate	FB Rate	LD Rate	PU Rate	HR/FB	wOBAcon
Sinker	.554	.260	.167	.020	.094	.298
Fastball	.469	.224	.235	.071	.000	.231
Cutter	.582	.184	.122	.112	.000	.269
Changeup	.365	.297	.243	.095	.091	.304
Curveball	.519	.185	.222	.074	.400	.448
	.516	.237	.186	.061	.075	.285

The three kinds of fastballs are all more or less thrown to contact; they are typically around the strikezone and generate grounders at a solid rate.  The changeup may be Buchholz's best strikeout pitch with that insane whiff rate.  In case you were wondering, his change was the second hardest pitch to hit among pitches from qualified starters last year (Cole Hamels's changeup was best with a whiff rate of 48%).  The curve isn't thrown for a strike very much and, overall, wasn't a very effective pitch last year.

This next chart shows Buchholz's pitch selection in each ball/strike count:  

No big surprises here - in strikeout counts, hitters might get any of Buchholz's five pitches (though he doesn't seem to trust the curve enough to throw it in full counts).  

As I said, there's a lot to like about Buchholz: he gets groundballs, he can consistently throw four of his five pitches for strikes, and he has a top-flight strikeout pitch in his changeup.  Still, if he maintains his peripherals from last year, one would expect his ERA to rise by about one and a half runs per nine innings.