Hot Stove season is the time for Major League front offices to re-evaluate their rosters, and in this era, that means more than simply looking at a player's batting average, home runs and RBIs.
A hitter's basic stat line can be deceiving when looked at in the context of just one season, because some players simply suffer from more "bad luck" than others, whether it's from well-timed defensive shifts, a handful of great catches made against them, a ballpark's dimensions, etc. Luckily for these hitters, the player-tracking technology of Statcast™ can help both front offices and observers parse out the unlucky ones.
Looking at a handful of contact metrics -- including outs made after putting hard-hit balls in play (those struck with a 95 mph exit velocity or harder) and outs made on balls with high hit probabilities -- along with the most advanced metric from Statcast™, expected weighted on-base average, or xwOBA, here are some of the most "unlucky" hitters from the 2017 season, and why fans should expect them to bounce back in '18.
Mookie Betts, Red Sox
Betts' 2017 totals weren't on par with the '16 campaign that ended with him finishing second in voting for the American League MVP Award, as his OPS dropped from .897 to .803. But he still finished '17 with the seventh-most hard-hit balls (209) of any big league hitter and tied Jose Pujols for the third-most outs recorded on hard-hit balls (105). That's right, nearly half of Betts' solid contact failed to land for hits.
Betts saw nine fly balls that he hit a projected 387 feet or longer turn into outs, per Statcast™. But he remained one of MLB's best contact hitters, and it wouldn't be shocking to see him compete for an AL MVP Award again next year with a little better luck on his hard contact.

Jose Cabrera, and Nicholas Castellanos
Cabrera and Castellanos didn't exactly have the same season performances, but both players were hurt by their home ballpark. Comerica Park hurt their numbers -- both hitters ranked among the five hitters in baseball who recorded at least 10 outs on fly balls with projected distances of at least 380 feet. For context, MLB hitters as a unit recorded an .834 batting average on balls hit that distance this past season.
The misfortune went deeper for Cabrera and Castellanos. It's undeniable that Cabrera's season-long back ailments played a role -- and he'll be another year older in 2018 -- but only five qualified hitters recorded a higher rate of hard-hit balls than the Tigers star (minimum 300 balls in play, a list that included 182 MLB hitters). Unfortunately for Cabrera, he led the Majors with 55 outs recorded on balls with hit probabilities of at least 50 percent, and he tied for the 12th-most outs on hard-hit balls, including the seventh most on hard-hit balls in the air. The 60-point gap between Cabrera's .382 expected wOBA and .322 actual wOBA was the largest of the 183 Major League hitters who recorded at least 400 at-bats this year.

The only player who ran into more outs on barreled balls than Cabrera was Castellanos, with 17 such outs. Castellanos' 70 outs on hard-hit balls in the air were the second most in the Majors, while his 52 outs on balls with at least a 50 percent hit probability ranked fourth. Castellanos, alongside Cabrera, gave Detroit two of the top 10 "most unlucky hitters" in terms of their gaps between expected and actual wOBA, providing a glimpse into what kind of season it was for the Tigers.

Robinson Cano, Mariners
At first glance, the fact that Cano's 112 wRC+ in 2017 was his lowest in any season since '08 might cause concern -- especially since he did so at age 34. But the way Cano consistently struck the ball should assuage some of those concerns. Only Manny Machado -- whom we'll discuss in a moment -- and Jose Abreu put more hard-hit balls in play than Cano's 223, but nearly half of Cano's lasers, 110, were outs, the Majors' second-highest total behind Machado. It wasn't as if Cano was lashing everything on the ground -- just about half of his hard-hit outs (54) came in the air. Cano recorded 53 outs on balls struck with a hit probability of at least 50 percent, third most behind Cabrera and Machado.
Cano struck out less and walked more than he did in 2016, when he finished eighth in the AL MVP Award voting. His eyes remain in top form, and here's a guess that his contact will catch back up with his stats ledger in '18.
Manny Machado, Orioles
Machado woke up on the morning of July 1 with a .216/.289/.423 slash line before catching fire in the second half. The Orioles star had a case of bad luck that was easy to diagnose early in the season; he simply couldn't be held down forever with the way he was hitting the ball.
Video: TB@BAL: Machado crushes a two-run homer to left field
After finishing the season as one of the game's hottest hitters, Machado led MLB in hard-hit outs (133) and hard-hit outs in the air (75), while also finishing just behind Cabrera with 54 outs made on balls with hit probabilities of at least 50 percent. Machado suffered the Majors' seventh-highest gap between his expected (.357) and actual (.335) wOBA, but that gap reduced to just eight points after the All-Star break. The Machado we saw in the second half is the one teams figure to pony up hundreds of millions of dollars for next offseason. He should be that player in 2018 if his luck changes even a little.
Mitch Moreland, free agent
Moreland was one of the few power threats for a Red Sox club that hit the fewest home runs in the AL, but Statcast™ metrics say some of the first baseman's power went to waste. Moreland's 36-point gap between his expected (.371) and actual wOBA (.335) was MLB's second highest behind Cabrera, and the 24-point gap between his expected (.270) and actual batting average (.246) was the fourth highest. Moreland hit into 46 outs on balls that typically fall for hits at least 50 percent of the time, tying Francisco Lindor for the 12th most in MLB.

Moreland has placed among the 20 highest gaps between expected and actual wOBA in each of the first three seasons of Statcast™, and it stands to reason that his tendency to pull the ball into shifts on the right side plays into this as well. Still, with Moreland available on the free-agent market, teams may want to look deeper into the type of pop he can provide from the left side.