16. Tampa Bay Rays (5–2, plus-7)
From the first time he toed the rubber in the big leagues back in 2012, Chris Archer has always wielded a devastating slider and it has always been his best pitch. No American League pitcher generated more value from their slidepiece in 2015 and '16 than Archer did, and no AL pitcher threw one more often.
The problem is that this huge reliance on the slider also stems from another reason: His fastball can be incredibly erratic. When Archer threw a league-average fastball in 2015, that combined with his unhittable slider was enough to make him one of the best pitchers in baseball (he ranked sixth in the AL that year in park-adjusted, fielding-independent pitching). Last season, Archer tossed the seventh-least effective fastball in the AL . . . and both his ERA and fielding-independent numbers jumped by nearly a full run.
So far, so better in 2017. Archer’s strikeouts are down a bit in his first two starts of the season, but he’s made for it by hiking his groundball rate to a career-high 52.5%, with less hard contact against him than ever before. And in the incredibly early going, Archer has stifled opponents’ batting average more effectively with his heater than his slider. That’s a great sign for a bounceback season, both for the Rays ace, and for his team.