Fantasy Implications of the Splits Leaderboard

Yesterday, FanGraphs made public its splits leaderboard, which the authors have been able to test and refine in private for some time now. It’s an incredible tool. If you haven’t checked it out, you should. If you haven’t thanked Sean Dolinar for building it, you should. (If you have any preliminary feedback, leave it in the comments and I’ll pass it along.)

There are a seemingly infinite number of ways to cross-cut data in endlessly fascinating ways. Splits by handedness, situation by outs, situation by leverage, situation by defensive alignment (shift or no shift!) — the list goes on. But the thing that most interested me immediately was understanding the implications of more granular batted ball data.

Two tools I once refined/created — xBABIP and xISO — rely almost exclusively on Baseball Info Solutions (BIS) batted ball data. Yet they were limited in their capabilities because of the limited nature of the data: we knew each hitter’s contact quality (hard/medium/pull) and contact direction (pull/center/oppo) but now how the trios intersected. But, ah, the splits leaderboard.

The following tables depict the batting average on balls in play (BABIP), isolated power (ISO), and home runs per fly ball (HR/FB) in 2016 by each cross-section. (Tony Blengino may have summarized these statistics a long time ago on the main portion of the site, but his series on contact quality is expansive, thus making the inaugural posts difficult to trace.)

Unsurprisingly, better contact quality produced more hits. Balls in play to different areas of the field produced varying rates of hits, but not dramatically so. Dissect these a bit more, though, and there’s quite a bit of variation within each batted ball direction. Pulling the ball is something of an all-or-nothing affair, so if you’re going to pull it, you better make good contact. Hitting to center and opposite fields is a bit more forgiving, especially for middling contact up the middle. Of course, none of this factors in handedness — soft pull contact for lefties (and, similarly, weak oppo contact for righties) may have even worse BABIPs when considering defensive shifts effects, should they exist.

Batted ball quality and direction have huge implications on a hitter’s power. Despite the lack of granularity within each of these bins — an area in which fancy new StatCast data prevail — it’s evident one can still draw meaningful conclusions from them. It appears that anything but hard contact is almost worthless in terms of extra-base hits, and hits to the pull side produce ISOs significantly higher than up the middle or to the opposite field. (Unsolicited aside: That’s why you shouldn’t give up too early on guys like Michael Conforto.)

Here’s the sequel to the ISO story. Among hard-hit fly balls and line drives, those to the pull side result in home runs more than three times as often as those up the middle and to the opposite field. Among all degrees of contact quality, it increases to four times more (up the middle) and eight times more (oppo).

It’s fairly intuitive why my equations rely heavily on hard hits and the pull side. I have presented this data to validate the theory behind those models. However, despite building these equations, I’m not really one to use them very often. I’m more of a freehand kind of guy; I’ll glance at a hitter’s pull rate (Pull%), hard-hit rate (Hard%), and fly ball rate (FB%) to glean a general understanding of his power profile. Now, I can do that, but with more precision.

You can use these tables to compare players against the league baseline or or the splits leaderboard itself, to compare players among one another, or even themselves. For example, Nelson Cruz hit home runs a perfect 26-for-26 on pulled, hard-hit fly balls. If you’re wondering if he’ll do that again, perhaps it’s worth comparing Cruz to his past self: his HR/FB on such batted balls was 81.5% in 2015, 71.4% in 2014 and 66.7% in 2013. (It’s not as efficient as using Nelly’s splits tool, which exists for him and also every player on their respective pages, but it gets the job done nonetheless.)

I likely won’t update xBABIP and xISO any time soon. The splits leaderboard should sustain us a while. Until then, I hope the preceding tables are helpful and equally inspirational — like Baseball Reference’s Play Index, you could use it for hours on end.