Among fantasy owners, batting average on balls in play -- or "BABIP" -- has become one of the most oft-used advanced stats to predict future value. However, wise owners know that not all BABIPs are created equal.
By providing a batting-average figure sans home runs and strikeouts, BABIP measures factors over which hitters have less control. Players can experience dramatic swings in performance based on batted-ball luck, which often evens out over time. When determining a player's future batting average (and also his likelihood of generating counting stats), owners should first determine if that player's recent performance was heavily impacted by an abnormal BABIP.
But said assessment becomes more complicated with the realization that high BABIPs do not automatically forecast a decline and low BABIPs are not certain to rise in the future. Rather, a player's individual skill set -- his power, speed and batted-ball tendencies -- will impact his "normal" BABIP.

The following 10 men experienced an extremely high or low BABIP in 2016. By taking a closer look at their skill sets and career patterns, we can determine their likelihood of experiencing major regression -- either positive or negative -- in the coming season.
Players with a high BABIP in 2016
J.T. Realmuto, C, Marlins: With a .303 average and 12 steals, Realmuto overcame a lack of difference-making power (11 homers) to rank among the most valuable fantasy catchers last season. But his batting average may have been unsustainably high thanks to a .357 BABIP -- which greatly exceeded his .288 mark over 2014-15. Yet to demonstrate the ability to post elite line-drive or hard-hit rates, Realmuto will likely experience a drop in batting average as his BABIP regresses next season.
Yadier Molina, C, Cardinals: Although he fell short of a double-digit homer total for the third consecutive year, Molina helped '16 mixed-league teams by tying Wilson Ramos for the highest average (.307) among catchers who qualified for the batting title. However, his success was fueled by a BABIP (.335) that was substantially higher than his lifetime .300 mark. As a ground-ball-heavy hitter without plus power or speed, Molina may struggle to hold a lineup spot in one-catcher leagues next season.
DJ LeMahieu, 2B, Rockies: LeMahieu led the Majors in both batting average (.348) and BABIP (.388) this past season, as he combined a low fly-ball rate (22.8 percent) with a career-high 35.2 percent hard-hit rate. Having also posted a lofty .362 BABIP in '15, LeMahieu could use his contact skills and Colorado's hitter-friendly home park -- where he hit .391 last season -- to avoid major regression next year.

Jonathan Villar, 3B/SS, Brewers: On his path to a top 10 ranking among all fantasy assets last season, Villar was greatly helped by the fourth-highest BABIP (.373 BABIP) in baseball. Though the switch-hitter should use his fleet feet and heavy ground-ball lean to produce a solid batting mark again next year, he is set to experience some regression in the BABIP and HR/FB rate (19.6 percent in '16) arenas. Rather than expecting the infielder to repeat last year's 19 long balls and 62 stolen bases, wise owners will instead project him to finish near the 10-homer and 45-steal marks.
J.D. Martinez, OF, Tigers: After Martinez produced a .307 average that was fueled by a .378 BABIP last year, fantasy owners may be tempted to project him for a significant decline. But upon closer inspection, owners can see that the slugger has used a penchant for making hard contact to log a .366 BABIP across three seasons with the Tigers. Although the 29-year-old may regress some in 2017, his dropoff will likely be more minimal than that of the others on this list.

Players with a low BABIP in 2016
Joe Panik, 2B, Giants: Owners who were counting on Panik to boost their 2016 batting average instead saw him hit just .239. True, his struggles can be partially ascribed to drops in his line-drive and hard-hit rates. But the second baseman was also plagued by a .245 BABIP that was 91 points lower than his .336 mark from 2014-15. One of the toughest in baseball to whiff (career 9.8 percent strikeout rate), Panik could use better batted-ball luck to return to his high-average ways next year.
Todd Frazier, 3B, White Sox: Despite recording 40 home runs, 98 RBIs and 15 steals in 2016, Frazier fell short of the elite tier among fantasy third basemen due to a .225 average. Though the veteran had his performance depressed by a career-worst .236 BABIP, wise owners will look at his underlying metrics before expecting a major rebound next year. By combining a lofty fly-ball rate with a pull-heavy approach and an unimpressive hard-hit rate, the 30-year-old has concocted a recipe for regularly producing routine outs.
Bryce Harper, OF, Nationals: Among the biggest fantasy disappointments last season, Harper experienced an 87-point batting-average slide that corresponded with an eye-popping 105-point drop in BABIP (.369 BABIP in 2015; .264 BABIP in '16). Although the superstar slugger produced fewer line drives and hard-hit balls in '16, his extreme change in batted-ball fortune is unlikely to continue into next season. Thus, the 24-year-old could be on the verge of a major bounceback campaign.

Jason Heyward, OF, Cubs: After producing solid statistics in 2015, Heyward seemed set for a terrific '16 season as the No. 2 hitter in a talent-laden Cubs lineup. But the outfielder wound up on waivers in most leagues as he hit .230 with meager counting-stat totals. While expectations must be tempered after that showing, the 27-year-old could return to mixed-league relevance if he sees last year's .266 BABIP and 4.8 percent HR/FB rate move toward his respective lifetime .302 and 11.6 percent marks.
Curtis Granderson, OF, Mets: While he slugged 30 home runs, Granderson failed to make a major mixed-league impact due to his low RBI total (59) and .237 batting average. However, the veteran could have been a better overall asset last year if his .254 BABIP had been similar to his lifetime .296 mark. Yes, Granderson has posted a BABIP of .265 or lower in three of the past five campaigns thanks to his fly-ball and pull-happy tendencies. But his 37 percent hard-hit rate across the past two years suggests he will likely be less of a batting-average drain in 2017.