A week ago, I introduced the newest version of our ever evolving xBABIP equation, this time incorporating the much-needed shift data. Last Thursday, I identified the 10 fantasy relevant hitters with the greatest BABIP upside in 2017, given the gap between their 2016 BABIP and xBABIP. In the comments, I was asked if I could perform a retrospective analysis to see how the new equation would have done if I ran it heading into the 2016 season.
I’ll start by looking at all hitters that posted an xBABIP of at least 0.030 above their actual BABIP marks in 2016 (e.g., a .300 xBABIP vs a .270 actual BABIP), which totaled 39 batters. I also included 2016 Steamer projections to determine whether xBABIP is truly providing any incremental value. So here we go.
|Name||2015 BABIP||2015 xBABIP||2015 BABIP-xBABIP||2016 Steamer Projected BABIP||2016 BABIP||2016 BABIP – 2015 BABIP|
Obviously, there’s little need to dive into any specific names here. Of the 39 batters who underperformed the most, only five of them posted 2016 BABIP marks below their 2015 BABIP marks. That means that 34 of the 39 (87%) of these underperformers increased their BABIP marks!
The most important row is “Averages”. You can see that the group suffered from some awful BABIP fate in 2015, posting an unweighted (I ignored at-bats for simplicity) BABIP of just .254. However, xBABIP thought these hitters should have enjoyed much greater success, figuring a mark of .300, right near the league average. On average, these batters underperformed their xBABIP marks by a whopping 0.046 points. That’s bad! But perhaps greener pastures were in their future.
Being rather familiar with BABIP, we would typically look at an average at .254 and almost blindly forecast an increase the following season. So gee, xBABIP thinks guys averaging a .254 BABIP will improve in 2016? I could have guessed that myself! That’s why I included the Steamer projected BABIP, and you’ll learn that the best projection system did indeed forecast vast improvement to .286. It’s interesting to note that Steamer doesn’t even project batted ball distribution (FB%/GB%, etc.), so it’s not like the system is observing a high line drive rate relative to BABIP and expecting better results.
Yet, Steamer’s projected improvement actually proved not to be optimistic enough! Move one column over and you see the group actually posted a .301 BABIP, 15 points higher than Steamer projected and nearly dead on with their 2015 xBABIP.
So the early return suggest that the new xBABIP does provide additional value over and above Steamer. And guess what? The BABIP forecasts in my Pod Projections reflect the new xBABIP equation, which should help boost their accuracy.
Mike Podhorzer is the 2015 Fantasy Sports Writers Association Baseball Writer of the Year. He produces player projections using his own forecasting system and is the author of the eBook Projecting X 2.0: How to Forecast Baseball Player Performance, which teaches you how to project players yourself. His projections helped him win the inaugural 2013 Tout Wars mixed draft league. Follow Mike on Twitter @MikePodhorzer and contact him via email.