We're all familiar with slugging percentage and how it values extra base hits over singles. Expected slugging percentage is a newer stat that attempts to identify a player's skill more so than regular slugging percentage, as xSLG removes defense from the equation. Since batters have control over their exit velocity and launch angle, but not what happens to a batted ball once it is put into play, there is some value in using Statcast's measurements to identify quality of contact.
Many fantasy baseball owners are starting to see the value of MLB's Statcast advanced stats in order to help identify potential risers and sleepers. Just as we've done for pitchers, this weekly series will examine a handful of hitters who are performing surprisingly well or poorly according to sabermetrics.
Each week, we'll take a look at some key Statcast offensive metrics in order to assess risers and fallers. This time, we'll check out some expected outcomes and compare them with actual outcomes by looking at xSLG - SLG to see where the biggest differences lie. The threshold for qualifiers will be 50 plate appearances (PA).
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Surprising Chart Toppers
All stats current as of June 18, 2018 and display leaders among hitters with at least 50 PA
Alen Hanson (2B/OF, SF) 0.221 xSLG - SLG
Hanson is a surprising name on any slugging list, but he tops the charts by far on this list, with more than double the difference of the next highest player (Almora). Hanson has a crazy .325 ISO and .636 SLG due to 14 extra-base hits in 77 at-bats. He ranks all the way down at 216th for xSLG, however, which makes much more sense. He's been all-or-nothing as a Giant, tallying a mere 9.4% Line Drive rate, yet posting impressive numbers. His sporadic usage may explain why he's yet to settle into any sort of identifiable pattern, since he's frequently used as a late-inning sub and/or pinch-hitter. Hanson does have some pop, but until he becomes an everyday player we shouldn't make too much of his sudden slugging prowess.
Albert Almora Jr. (OF, CHC) 0.101 xSLG - SLG
On the surface, Almora's slash line of .321/.369/.439 is pretty good, especially considering the lineup he's in. Statcast begs to differ. His .338 xSLG ranks 332nd and his 85.8 mph exit velocity ranks 307th. To add insult to... insult, Almora's average HR distance on his two bombs are lower than every player who's gone deep this year except eight, and one of those is Dee Gordon. Almora isn't bringing any power or speed to the equation, so that high average based on a .381 BABIP doesn't mean a whole lot.
Joc Pederson (OF, LAD) 0.096 xSLG - SLG
He's been one of the hottest hitters plucked off waivers lately, but it's time to get off Joc's jock. Pederson has always had power, but decided to sit out the first two months in the home run department before launching seven homers in the first two weeks of June. He does have his exit velocity over 90 and a decent hard-hit percentage, but the launch angle has been inconsistent. This is by design too. Pederson has been more patient at the plate, cutting his strikeout rate in half from two years ago. He's also trying to keep the ball upright more often rather than rolling over on it, which led to a 46.6% ground ball rate and a .212 batting average last season. It worked, as he kept his average afloat and drove in some runs to start the season, but the power disappeared. Now, he's starting to elevate it once again and it's paying off. The problem is that he only brings it in select moments, namely against right-handers. Pederson will not hit, or often play against, left-handers, which limits his value. He is also just as likely to revert to his free-swinging ways and recapture those bad habits. His low xSLG shows that he is nothing more than a short-term play for a quick HR boost that may have already passed.
Austin Meadows (OF, PIT) 0.092 xSLG - SLG
The rookie is slugging a whopping .620 thanks to five home runs, a pair of triples, and six doubles in his first 25 MLB games. He's one prospect pickup that has definitely paid off, but will it continue? Although the sample is still small, the outlook is good. Meadows has a robust .534 xSLG, is in the upper half among the leaders for Barrels/PA and Hard%, and is only striking out 15.2% of the time. It might be premature to assume he's fully developed his power stroke at just 23 with only a quarter of a season under his belt, so temper expectations in the HR category, but buy him as a long-term offensive threat for the remainder of this season.
Alarming Bottom Dwellers
Steve Pearce (1B/2B/OF, TOR) -0.241 xSLG - SLG
Pearce immediately stands out as a player that just doesn't belong at the top of the xSLG list among Mookie Betts, J.D. Martinez, Mike Trout, and Freddie Freeman. Pearce is second only to Betts in terms of expected slugging, but owns a .485 slugging percent with just three homers. Pearce is 15th on the Barrels leaderboard and has a strong 27.3% LD%, which means he is crushing the ball regularly, but his launch angle is too low to generate enough XBH. As a role player and an aging vet, Pearce is nothing more than a DFS flier on days he has favorable matchups, even if he can still bring the wood.
Kole Calhoun (OF, LAA) -0.173 xSLG - SLG
It is now verifiable that Calhoun's 2015 power surge qualifies as his career year and an outlier on an otherwise mediocre fantasy resume. This might be the year that removes him from the equation altogether. What's the worst part - one home run in 185 plate appearances, a .145 average, a 0.26 BB/K, or just the fact that the Angels keep him in the lineup? His putrid .352 xSLG shows that things should be even worse than they are now, if you can believe it.
Matt Carpenter (1B/2B, STL) -0.136 xSLG - SLG
If you read this week's Buy or Sell, you know where I stand on Carpenter. The issue has always been health, so as long as he's not showing signs of being slowed by a shoulder or back injury, he belongs in fantasy lineups. Carpenter went deep on Father's Day for his 10th jack of the year, a number that could continue to grow as the season progresses. He already ranks fourth among all qualified hitters in Hard% despite the rough start to 2018. In this case, throw out the first month's statistics and follow what he's done over the last few weeks to get a sense of his true worth.
Chris Davis (1B, BAL) -0.126 xSLG - SLG
You knew this was coming. Davis isn't being touched with a 90-foot pole by fantasy owners these days, but that was long overdue. I listed him as a hard sell just two weeks into the season, in fact. He is currently 309th in xSLG, just ahead of Calhoun. His exit velocity is down two ticks, putting him 226th overall after ranking 35th last year and 53rd the year before. When a pure slugger is hitting the ball on the ground nearly half the time and sees his walk rate plummet below double digits, you know things are bad. Now that he's been officially removed from the lineup with no return in sight for the near future, there is no excuse to stash him no matter how deep your rosters may be.