xStats Projects 5 Cubs to Hit At Least 20 Home Runs
Most projection systems match a player with a historical comparison, but not Andrew Perpetua’s xStats. Instead, the Statcast-centric model projects players as followed:
[xStats 2017 estimates] are calculated by giving the 2015 batted balls a weight of 0.92 and 2016 batted balls a weight of 1.00. All batters are given 600 PA by default and all pitchers 150 IP.
In other words, Perpetua’s 2017 projection model simply averages the previous two years of data, but weighs the most recent year most heavily.
xStats works by converting exit velocity, launch angle, and batted ball location into an expected stat. You might have seen the advent of Statcast’s new “hit probability” metric, but their model doesn’t incorporate both vertical and horizontal angle like Perpetua’s xStats does.
Anyway, how do the Cubs project in 2017 based on the previous two years?
| Name | Sample | PA | xAVG | xOBP | xBABIP | xOBA | xHR | xHR/FB |
| Anthony Rizzo | 1409 | 600 | .268 | .356 | .282 | .360 | 25.3 | 23.1% |
| Kris Bryant | 1376 | 600 | .260 | .346 | .307 | .366 | 33.7 | 29.4% |
| Ben Zobrist | 1235 | 600 | .275 | .362 | .295 | .342 | 12.6 | 14.9% |
| Jason Heyward | 1215 | 600 | .266 | .333 | .303 | .312 | 9.8 | 14.1% |
| Addison Russell | 1128 | 600 | .230 | .291 | .280 | .296 | 19.6 | 21.5% |
| Miguel Montero | 710 | 600 | .215 | .304 | .263 | .288 | 16 | 16.9% |
| Jon Jay | 617 | 600 | .258 | .311 | .315 | .290 | 6 | 9.1% |
| Javier Baez | 538 | 600 | .245 | .268 | .300 | .283 | 18.7 | 21.2% |
| Kyle Schwarber | 309 | 600 | .234 | .342 | .278 | .348 | 33.2 | 37.2% |
| Matt Szczur | 279 | 600 | .255 | .296 | .301 | .292 | 12.7 | 10.3% |
| Willson Contreras | 279 | 600 | .247 | .319 | .292 | .326 | 23.2 | 28.4% |
| Tommy La Stella | 254 | 600 | .253 | .324 | .275 | .324 | 16.6 | 16.0% |
If some of these numbers look underwhelming, keep in mind the inherent shortcomings of such projections. While xStats measures precisely what it seeks to quantify, no system can capture behavioral and mechanical adjustments players — particularly those at a young age — will make.
I’m looking at you, Addison Russell, what with that projected .296 wOBA in 2017 despite 20 homers.
Even though some on the list have surprisingly low numbers, Tommy La Stella is actually projected to own a .324 wOBA, almost 12 points better than Jason Heyward and 41 points better than the Cubs’ heroic postseason second baseman, Javier Baez. This doesn’t bode well for La Stella’s roster-spot competition, Matt Szczur, who is only projected to have a .292 wOBA.
Finally, xStats believes the Cubs are loaded with power. Kris Bryant, Anthony Rizzo, and Kyle Schwarber are projected to hit 34, 25, and 33 homers, respectively. Even Willson Contreras is projected to have 23 homers. And Baez is only one homer shy of Russell. That means the Cubs have five projected 20-homer hitters, with Baez lurking just behind.
That would make 154 dingers from only six players, 81 shy of the club-record 235 posted in 2004. Might be a fun goal to track alongside the pursuit of another divisional crown.