2013 AFL Pitch F/X Data: Velocity

In the previous post, I look at the locations of pitches in the Arizona Fall League. In this one, I wanted to continue to look at the data of the 110 pitchers by focusing on velocity. First, here is a graph that breaks down both the pitch selection (by percentage) and average velocity of all pitch types thrown in the Pitch F/X games in the Arizona Fall League:

For comparison, here is the MLB averages according to FanGraphs in 2013:

There were no knuckleballs, knucklecurves, screwballs, eephus, or forkballs thrown in the AFL according to the MLBAM tags. FanGraphs has also kept the old fastball label (FA) instead of moving to the FF. The FAs in the AFL are most likely errors.

While changeups are very slightly slower in the AFL (.03 MPH), they were actually used more frequently in the AFL, which I found surprisingly. Curves were thrown at the same velocity, but less frequently in the AFL, and there were less cutters and sliders as well. It appears that there was a higher volume of four seam fastballs, though they were thrown at half a MPH slower.

What about individual pitchers? Who were some of the hardest throwers in the AFL? Here are the fastest 50 pitches in the AFL tracked by Pitch F/X in 2013:

The fastest 27 pitches were either thrown by Keone Kela or Ken Giles. Giles was a 7th round draft pick in 2011 by the Phillies, and the right-hander has been almost exclusively a reliever in his minor league career and he hasn't yet reached AA. He has struggled with walks, but has put up gaudy strikeout numbers. Kela has been profiled on the blog before, but his 2013 season only contained 39 innings over three different levels (though his strikeout rate was great). Juan Jaime had the only two pitches out of the top 39 fastballs not thrown by Kela or Giles. Jaime is already 26, and the Braves' right-hander has struggled to put a full season together, just making AA in 2013. He had high walk and strikeout numbers.

How about the slowest 50 pitches in the AFL?

Kevin Vance and his slow curve had a good year in AA for the White Sox out of the bullpen, and he has racked up plenty of strikeouts. Mike Morin also had several of the slowest pitches in the AFL, and he is coming off of a great year in the Angels system with an ERA under two and reaching AA.

Of course, we haven't looked at individual pitch types yet, so broken down by pitch type, MLBAM tags, here are the fastest individual pitches per each type:

Lendy Castillo reached the Majors with the Cubs in 2012, but struggled. In 2013, he actually spent most of the year in the lower minors and struggled there as well. Adys Portillo doesn't turn 22 until December, but is coming off a lost year with just 3 appearances (just starts) in A-ball. Shawn Armstrong, an 18th round pick by the Indians, had a tremendous year in 2012, but spending most of 2013 in AA, had a very mediocre year by ERA because of walks, but he continued to strikeout batters. Matt Heidenreich was acquired by the Astros in the Brett Myers trade, but had a horrendous 2013. Alex Meyer is one of the top pitching prospects in baseball, but had a shortened year in AA.

The slowest pitches by each type:

I think there are some Pitch F/X errors here, and it seems to have mistreated Miguel Pena of the Red Sox. However, scouting reports have described him as a pitchability guy with a fastball mainly in the 80s, so perhaps these low readings aren't unbelievable.

While we haven't looked at results or hitters yet (I plan on taking a deeper look later), I thought it would be interesting to see whether or not there was a correlation between faster fastballs and success in the AFL, like we see in basically every level of play.

Not surprisingly, the harder the fastball, the more likely it is to be a whiff, and the softer, the more likely it turns into a run scoring play (though the out versus no out distinction is fuzzy at best).

What about pitches on the whole, regardless of classification? One would expect that younger hitters would struggle with slower pitches, fooled by breaking balls, and hitting fastballs better. It turns out, this is the case for the most part:

Batted ball results don't make as much sense as they do with the fastballs, but the pattern is clear. Batters were more likely to hit faster pitches, or at least, fastballs over breaking balls and offspeed pitches.