Hitter Analytics Updates

Recently, I made an initial push to get a deeper look at hitters. I felt people have enough information on pitchers, especially with the Pitchf/x data available. I finally had some time to dig into the information a little more and have come up with a couple updates.

Nine batted ball categories is too many

Inside Edge makes avaialble nine non-bunt categories for batted balls. Here are the original nine with the xBABIP and wOBAcon:

Batted Ball Type: xBABIP, wOBAcon, % of batted balls
Groundball – Weak: .151, .112, 31.4%
Groundball – Medium: .461, .416, 9.5%
Groundball – Well-Hit: .647, .610, 3.8%
Line Drive – Weak: .622, .579, 2.3%
Line Drive – Medium: .650, .638, 7.3%
Line Drive – Well-Hit: .719, .815, 11.1%
Flyball – Weak: .078, .074, 18.5%
Flyball – Medium: .069, .081, 8.2%
Flyball – Well-Hit: .641, 1.168, 7.8%

Some of the results are basically the same like with Weak and Medium Fly Balls and Weak and Medium Line Drives. Besides aiming for categories with similar results, I felt some groups had too small of a data sample like the 2.3% of batted balls being Weak Line Drives. I would like the categories to have around 10% of all batted balls to help find similar hitters.

Here are the six types I came up with (these values are updated with the 2015 values so far).

Batted Ball Type: xBABIPwHR, wOBAcon, Overall %
Hard FB: 0.641, 1.162, 7.6%
Hard LD: 0.719, 0.820, 11.0%
Hard GB and Weak and Med LD: 0.644, 0.619, 13.6%
Medium GB: 0.461, 0.423, 9.6%
Weak GB: 0.151, 0.116, 32.0%
Weak and Medium FB: 0.075, 0.074, 26.3%

These categories have a nice hiearcial structure with both xBABIP and OBAcon declining except right at the beginning with Hard-Hit Line Drives having a higher xBABIP. My biggest issue I have with this setup is including Hard-Hit Groundballs in with the Weak and Medium Line Drives. I based my desicion on the outcomes being similar and the amount of Hard-Hit Ground Balls being low (3.8%). I may be talked into combining the two groundball values, but I think the outcomes are far apart.

It is time to speak up about the categories if you see any issues. I will move to these categories this Sunday when I release the first set of 2015 values.

Stabilization Points

I really wanted to see if/when wOBAcon and xwOBAcon become predictive/stabilize. As a general note, I probably don’t have enough information to do a good stabilization point, but these can be a starting point.

  • wOBAcon (season 1) to wOBAcon (season 2): 315 batted balls
  • xwOBAcon (season 1) to xwOBAcon (season 2): 145 batted balls
  • xwOBAcon (season 1) to wOBAcon (season 1): 70 batted balls

We are getting closer to the 70 batted ball value in the 2015 season so the two in season values can be used. Targeting players whose production may change is getting close to being significant.


Is there anything else you would like changed from the previous format seen here? I am going to use the same basic format for the rest of the season.

Jeff, one of the authors of the fantasy baseball guide,The Process, writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won four FSWA Awards including on for his Mining the News series. He's won Tout Wars three times, LABR once, and got his first NFBC Main Event win in 2021. Follow him on Twitter @jeffwzimmerman.

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Paul C.
7 years ago

The re-grouping makes sense to me, but are the batted-ball percentages based on just results from this year, and if so, are there enough events to make you comfortable that they’ll stabilize at about the same hierarchy going forward? You could consider sticking with the nine categories a bit longer to see if the distribution stays about the same.