Mike Trout and Miguel Cabrera will not be participating in this year’s home run derby, with Cabera going as far as saying, “I don’t want to mess with my swing anymore.”
@ngreenberg are there any numbers to back up “HR derby screws up your swing” statement?
— John Wilkes (@WilkesonWarpath) July 9, 2014
Here are some stats of every player who participated in the home run derby from 2010 to 2013.
There is a big decline in isolated power, which measures a batter’s ability to hit for extra-base hits. However, that doesn’t always seem to be true for the league as a whole.
It’s easy to see why some would believe the home run derby can ruin a player’s swing: The data suggest that hitters do hit for less power in the second half of the season after participating in the home run derby. But does the derby itself play a role in the decline?
No, it doesn’t.
To help control for the luck involved in baseball, we can take a look at the differences in the way hitters put a ball in play before and after the home run derby. As you can see, it is pretty consistent.
Home run derby participants hit the ball almost the same both before and after the event. The biggest difference is in the home run-to-fly ball ratio, which would explain the decrease in batting average and isolated power.
The notion that participating in the home run derby can ruin your swing is a myth. Instead, it looks like hitters just get a little less lucky on the fly balls leaving the yard.