Swing Potency: Part 2

In part one, I looked at the relationship between swinging hard and making contact. I graphed contact percentage on swings inside the zone against wOBAcon (a measure of how hard a player swings) and found that there is in fact a notable relationship between the two – players who swing harder whiff more. For part two, I removed the small number of pitchers who accumulated over 500 PAs since 2002, which brought the r-squared up to 0.317.

I’ve updated the graphic, and highlighted the current Rays, along with recent ex-Rays Carl Crawford, Carlos Pena, Jason Bartlett, and Akinori Iwamura. See if you can identify which dot is who. Names are below the jump.

Click to enlarge.

Click to enlarge.

There are no real surprises here, except maybe that the dots for Dan Johnson and Casey Kotchman are so close to each other (and neither looks particularly like a first baseman). Everyone already knew that Evan Longoria has a potent bat, Kelly Shoppach swings hard but misses, and Sam Fuld rarely misses but doesn’t swing hard.

I think it is reasonable to hypothesize, based on the correlation shown here and on anecdotal evidence, that the hit tool and the power tool are interconnected, and can be talked about as a single skill. I’m choosing to call this skill “swing potency,” and to express it as the distance from a player’s dot on my graph of power vs. contact to the best fit line for all major league players. At the very least, this will allow for comparisons between the skills of such dissimilar players as Shoppach and Fuld. Here are the swing potency numbers for the Rays and ex-Rays players.

Keep in mind that this value is not scaled to anything, and has no meaningful unit. I make no claims to it doing a good job of describing overall hitter quality. It merely represents a hypothetical skill that is not directly observable (because in reality it is separated into power and contact ability). In part three I will investigate whether there is evidence that players can in fact redistribute their swing potency and to what extent. I will look at what redistribution along this line would mean in terms of actual offensive production, and at which Rays players should perhaps attempt to alter their profile.