Four plus pitchesby Mike Fast
June 23, 2010
|Strasburg readies a four-seam fastball against the White Sox on June 18. (Icon/SMI)|
Suffice it to say I'm not breaking new ground when I write about Stephen Strasburg and PITCHf/x, but I thought it would be interesting to combine the data from all five starts covered by PITCHf/x to see what we can learn about Strasburg's approach from a larger data set.
Strasburg throws four pitches: a four-seam fastball, a two-seam* fastball, a change-up and a curveball. Here are the pitch speeds and spin axis of the pitches he has thrown.
Another interesting way to look at his pitches is to see how they move. This chart shows the movement from the spin force and from gravity from 40 feet out to the front of home plate. The horizontal dimension is shown from the catcher's perspective.
His two-seam fastball also sits in the upper 90s, with an average speed of 97 mph. It has some nice sink for a pitch thrown that hard, with an average spin deflection of four inches of hop and nine inches of tail. It's not unusual for a pitcher to throw a two-seam fastball at the same speed or nearly the same speed as his four-seam fastball. What's unusual for a starting pitcher, obviously, is that he throws his fastball so fast. Strasburg uses the two-seamer most often to left-handed batters (27 percent of the time) and less frequently to right-handed batters (11 percent of the time).
*He has an interesting grip on this pitch, with his index and middle finger along one seam instead of each finger along a different seam. It's very similar to the grip that Jon Lester uses. In the interests of clarity, I'm going to call this pitch a two-seam fastball, but others, including Strasburg himself, have labeled this pitch a one-seam fastball (based on the grip).
His circle change-up comes in around 90 mph and has good drop. This pitch has an average vertical spin deflection near zero and eight inches of tail. He uses the change-up 13 percent of the time to right-handed batters and 20 percent of the time to left-handed batters.
|Strasburg spins a curveball against the White Sox on June 18. (Icon/SMI)|
Some have called Strasburg's breaking pitch a slider or slurve. It's not. I think they may have been deceived by the velocity on the pitch. A classic slurve is more like the sweeping breaking pitch thrown by Francisco Rodriguez or Carlos Marmol, about 10 mph slower than the fastball and with mostly horizontal spin deflection and little vertical spin deflection. An average starting pitcher throws fastballs around 90 mph, sliders in the low to mid 80-mph range, and curveballs in the high 70-mph range. Strasburg is not an average pitcher. At 83 mph, his curveball is 15 mph slower than his fastball. That's solidly in curveball territory. Moreover, the large negative vertical spin deflection on the pitch and the grip he uses are both classic curveball.
Next, let’s look at how he mixes his pitches in different ball-strike counts, which I’ve split out by batter handedness.
Strasburg likes to start off right handers with a four-seam fastball or a curveball, and if he gets Strike 1, he really likes to go the curveball, throwing it two-thirds of the time at 0-1. He brings out the change-up as his strikeout pitch, though he will also throw it at 1-0 or 1-1. When he gets behind in the count, he relies on his four-seamer, as do most pitchers.
Strasburg starts left handers with four-seam fastballs, two-seam fastballs and an occasional change-up. Whereas to right-handed batters, he uses the curveball early in the count, to lefties he's more likely to use it when he gets ahead in the count. His change-up, on the other hand, does not really get used as a strikeout pitch to left-handed batters; instead he tends to throw it as the second or third pitch in the at-bat. With two strikes, left handers are fairly like to see a four-seam fastball from Strasburg (53 percent four-seamers vs. 8 percent two-seamers), but earlier in the count the two-seam fastball is just as likely (35 percent four-seamers vs. 33 percent two-seamers).
What kind of results does Strasbrug get with each of his pitches?
Pitch Number Ball CS Foul SS InPlay BACON BABIP SLGCON HR Strk% Con% FB4 169 0.37 0.17 0.17 0.11 0.18 0.367 0.321 0.633 0.067 63% 77% Chg 65 0.38 0.05 0.09 0.37 0.11 0.571 0.500 1.000 0.143 62% 35% Crv 89 0.33 0.31 0.07 0.21 0.08 0.571 0.400 1.429 0.286 67% 41% FB2 78 0.37 0.12 0.27 0.06 0.18 0.143 0.143 0.143 0.000 63% 88%
The first thing to notice is that he throws all his pitches for strikes, including his off-speed pitches. League average is 60 percent strikes on change-ups and 57 percent strikes on curveballs, but Strasburg gets 62 percent and 67 percent. He's league average with his fastball at 63 percent strikes.
|Strasburg throws a change-up against the White Sox on June 18. (Icon/SMI)|
It probably comes as no surprise that his 98-mph four-seam fastball generates 11 percent whiffs, compared to league average of 7 percent. His two-seam fastball is more in line with league average in that department, but it produces a lot of foul balls.
Batters have had pretty good results against his off-speed pitches when they've put them in play, but that hasn't been often: 4-for-7 with one home run off the change-up and 4-for-7 with two home runs off the curveball. His two-seamer, on the other hand, has generated nine groundball outs and one bunt out against two line-drive singles.
Let's look now at where he locates his pitches to right-handed and left-handed batters. Strike-zone location charts are shown from the perspective of the catcher. The location of a pitch is indicated where it crossed the front plane of home plate.
Strasburg seems willing to challenge hitters in the zone with his four-seam fastball. He gets the most swings and misses when he gets the ball up, and left handers have swung at some fastballs at shoulder level. To right handers he does OK bringing the heat inside, but to left handers he does better keeping the four-seam fastball away.
He uses his two-seam fastball sparingly to right-handed batters, but when he does, he likes to keep it on the inside part of the plate where it's tailing in on the batter's hands. Similarly, he keeps the pitch away from left-handed batters, where it tails off the plate and away from the sweet spot on the bat. When he has dropped it below the zone to lefties on occasion, they've not done well, with three whiffs and a groundball out.
Strasburg keeps his change-up down. Down and in to right handers, down and away to left handers. Down. And the batters can't lay off of it, whiffing like crazy. I assume he must have pretty good deception. If the batters could only lay off his change-up, they'd be much better off. Of course, if it were that easy to lay off good diving change-ups, Lincecum wouldn't have two Cy Young Awards. On the other hand, on the rare occasions when Strasburg has left his change-up up in the zone, the batters have gotten a few hits off of it.
Strasburg uses his curveball often to right-handed batters, and he gets a lot of called strikes in the zone. Below the zone he gets a fair amount of swings and misses.
There has been some concern that Strasburg is getting a smaller strike zone from the umpires because of the unusual, and thus difficult to call, nature of his curveball. In truth, there's not much evidence of that. In the chart above you can see there is one ball that clearly should have been a called strike and a few very borderline ball calls that probably wouldn't have been called strikes for another pitcher's curveball, either. Granted, these charts show the location of the pitch at the front plane of the plate, but a typical curveball from Strasburg only drops about an inch while traveling 8.5 inches toward the catcher, so that doesn't change the picture by very much.
Runners on base
How Strasburg pitches with runners on base has been a topic of conversation. After Strasburg's start in Cleveland, Bob Feller observed, "He loses about two or three miles per hour on his fastball with men on base." I looked at the data for that from the game in Cleveland and found that there might be substance to Feller's comments.
However, this time around I wanted to look at the data for all five PITCHf/x starts instead of just one.
Runners Number FB4 FB2 Chg Crv FB4 Spd FB2 Spd LHB no 135 43% 23% 17% 17% 98.8 97.6 LHB yes 74 32% 34% 24% 9% 96.9 95.7 RHB no 132 53% 6% 11% 30% 98.3 97.7 RHB yes 60 28% 23% 17% 32% 96.7 96.2 both no 267 48% 15% 14% 24% 98.5 97.6 both yes 134 31% 29% 21% 19% 96.8 95.9
It turns out that Strasburg loses almost two mph on both his four-seam and two-seam fastball when runners are on base. I also looked for changes in spin deflection on his pitches with runners on base, but I didn't notice any significant changes in that arena.
In addition, we can see how his pitch mix changes with runners on base. With the bases empty, he favors the four-seamer over the two-seamer to lefties and uses the four-seamer almost exclusively to righties. When runners get on base, he abandons the curveball to lefties but sticks with it to right-handed hitters. He's also somewhat more likely to use the change-up with runners on base.
One thing I wanted to check, though, regarding the change in fastball speed, was whether the baserunners mostly occurred in the later innings when Strasburg was already losing velocity. In the Cleveland start, there was some indication that the two effects might be overlapping. In the larger data set, however, there isn't as much indication of this.
Here we can see Strasburg's fastball velocity by pitch number, for both the four-seamer and two-seamer. A few things stand out. First is that he loses one or two mph from pitch No. 10 to pitch No. 90. Second is that his velocity is lower with baserunners no matter how deep in the game. Thirdly, as we saw in the preceding table, he favors the four-seamer with the bases empty and the two-seamer with runners on, presumably in hopes of a getting a groundball double play.
Stephen Strasburg is a pitcher with amazing stuff and few apparent weaknesses. He throws four pitches for strikes with good movement and well-above-average velocity. As a rookie he presumably has much yet to learn about the art of pitching, knowing which pitch to throw when and how to read which way a batter is leaning. What he'll be able to do if he learns those things and keeps his phenomenal stuff, I can only imagine.
References and Resources
Thanks to Sportvision and MLB Advanced Media for the PITCHf/x data. Pitch classifications used in the article are my own.
Mike Fast is a Royals fan who enjoys investigating baseball questions using data of many sorts. He is a member of Complete Game Consulting. He welcomes comments via e-mail.