Justin Bour is going to participate in the Home Run Derby tonight. He’s tied with a bunch of other guys at 16th in baseball with 20 homers. He’ll surpass his previous career high early in the second half.
This is the point at which we normally address a crazy mechanical change a player’s made, allowing him to reach a new level of performance. That crazy change might not exist in Bour’s case, though.
The player himself doesn’t think there’s a big adjustment in his rear-view mirror. “From being in pro ball to now, I’ve only made minor changes to my swing, but for the most part, I’ve always just been myself and tried to get a little better every day,” Bour said before this past weekend’s series against the Giants.
There has to be some benefit from the fact that he’s not being platooned any more. “If I’m going to play every day, I’m going to put my numbers up,” he agreed. But that’s tough to pinpoint. Yes, the added plate appearances can help him put up larger counting numbers. That said, if that means greater exposure to left-handed pitchers, the platoon disadvantage could counteract the benefit.
And maybe it’s just the natural growth of a player. “The more you play in the big leagues, the more you learn the pitching, the more you learn yourself and what you can handle and what you can’t,” he pointed out.
The swing metrics don’t help us much, and it’s hard to argue that, at 29, age is on his side. But once he’s put the ball in play, there have been some small changes that would benefit his power numbers.
EV = exit velocity.
LA = launch angle.
But it’s hard to grasp anything here. He’s produced more solid contact, sure — and somehow that solid contact has more often occurred in the air — but the overall dimensions of his contact haven’t changed much. Exit velocity overall is down, and his launch angle has changed by one degree. Same tree-trunk quads, then and now.
One thing that has changed is the game around Bour. By the latest evidence, the ball looks to have lower seams, which means less drag in the air, which can explain as much as one-quarter of the home-run spike. How much of Bour’s current work could be explained in the same way?
Perhaps it could be! But it’s not as easy as just looking at the increase in exit velocity across the league — that’s up 1.02 mph over the last three years. Lower seams mean less drag and more distance on balls of equal exit velocity. We’re looking to account both for exit velo and drag.
Fortunately, we can approximate that by looking at the added distance on batted balls over the past few seaons. The league is hitting the ball five feet further on average since the beginning of 2015. According to Andrew Perpetua’s work, an extra foot of distance is worth about 0.2 mph itself. Hence, we’re probably looking at 1.11 mph of exit-velo adjustment. Put this year’s batted-ball information into the washing machine with these adjustments and out come this year’s expected outcomes, as if they were traveling through the air the same way they were in the first half of 2015.
In other words, what happens when we de-juice the ball and look at the player?
|Actual results in early 2017||305||0.289||0.367||0.556||20.0|
|Expected 2017 expressed in 2015 environment||305||0.280||0.359||0.518||16.9|
|Actual results in 2015||446||0.262||0.321||0.479||23.0|
So maybe Bour is about the same as he has always been, just a little better. Before this year, he was 16% better than league average with the stick. This year, the average first baseman is 13% better than the league average, so Bour is above average either way. It’s just that the peculiarities of the game around him have changed and made him look different.
Take him at his word, he hasn’t changed much. Still the same old Justin Bour. “Just going out there and whacking balls,” as he put it. “Sorry I can’t be more analytical.”
With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.