Thursday, July 15, 2010
Were the All Stars really throwing that hard?Posted by Mike Fast
If you watched the All-Star Game on Tuesday night, you may have noticed a lot high-nineties fastballs zipping from pitcher to catcher. At one point Fox put up a graphic listing the fastest fastballs of the night:
Pitcher Speed (mph) Price 100 Verlander 99 Johnson 99Some people wondered, particularly with David Price, whose average fastball speed this year is 95 mph, whether the Fox speed gun was "hot". I believe that Fox was actually getting its pitch speed data from PITCHf/x rather than a radar gun since the speeds that Fox reported match up very well with the speeds in the PITCHf/x data for the game.
Rather than looking at peak speeds, let's look at the average fastball speed for every pitcher who threw in the game.
Pitcher Speed (mph) Verlander 99 Price 98 Wilson 98 Johnson 98 Thornton 97 Broxton 97 Jimenez 97 Valverde 96 Wainwright 95 Kuo 95 Hughes 95 Bailey 95 Capps 94 Lester 94 Bell 94 Halladay 93 Soriano 93 Lee 92 Pettitte 91That's a lot of mid and upper-nineties fastballs! Of the 272 pitches thrown, 190, or 70 percent, were fastballs. The average fastball speed in the game was 96 mph. Wow.
Was the PITCHf/x system reporting pitch speeds accurately in the All-Star Game? The simple answer is, as far as I can tell, yes.
Many of the pitchers were definitely recording faster speeds than they had throughout the season. In addition to the aforementioned Price, Justin Verlander, Josh Johnson, and Adam Wainwright were each measured as bringing their heat two to three mph faster than during the season. The average fastball for all pitchers in the game was measured at one mph faster than the same pitchers threw during the season.
The initial inclination would be to say that the PITCHf/x camera system in Angel Stadium was out of calibration such that it was measuring pitch speeds about one mph too fast. That sort of error is not unheard of. However, we should also not be surprised if starting pitchers threw their fastballs harder than usual in short one or two inning stints or if the emotion of the confrontation with All-Star batters on a national TV stage was enough to give well-rested pitchers a little extra zip.
I don't know a simple way to determine whether either of those things are true, although we do see that the pitchers with the biggest boosts to their fastball speed were all starting pitchers. The average fastball speed boost relative to the regular season was 1.5 mph for starters and 0.4 mph for relievers.
Moreover, there are a couple things that I usually check when making adjustments to pitchers' fastball speed data in PITCHf/x. The first is the drag coefficient calculated from the PITCHf/x data. This is a physical constant that is dependent on things like the physical characteristics of the baseball but independent of a lot of other things, like the ballpark. The drag coefficient measured by the PITCHf/x system on Tuesday night was very close to the average expected value of 0.36.
The other thing I check is the average fastball speed of pitchers in a given game relative to their season average. But instead of simply doing it for a single game, as reported above, I do it for multiple games and look for trends. The average fastball speed recorded by PITCHf/x in Angel Stadium this year has actually been 0.8 mph less than the average fastball speed for the same set of pitchers pitching in other ballparks.
So, if anything, the "gun" in Angel Stadium has been a little cold in 2010. (I don't know whether the PITCHf/x system was recalibrated immediately prior to the All-Star Game, such that any bias in the data from earlier in the season would be irrelevant to the data collected Tuesday. We'll know more about that after we get data from the Angels' first homestand after the break.)
Fastball speed data is interesting, but we don't always know how accurate it is. In this case, although I can't give an official Good Housekeeping Seal of Approval, I don't see any convincing reason to believe that the speeds that Fox (and PITCHf/x) reported were juiced.
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.