Players are listed in descending order of games played in 2017.
Cody Bellinger, 1B/OF, Dodgers
A unanimous pick for the National League Rookie of the Year Award, Bellinger batted .267/.352/.581 with 39 homers in 132 games, despite only turning 22 on July 13. He smacked 45.7 percent of his batted balls with an exit velocity of 95 mph or harder, giving him the fourth-highest hard-hit rate out of 119 left-handers who put at least 200 balls in play. Perhaps more impressively for a hitter so young, that rate was slightly higher (47 percent) off left-handed pitchers, who yielded a .903 OPS to Bellinger.
Ian Happ, 2B/OF, Cubs
On one hand, the versatile switch-hitter missed on 34.4 percent of his swings, a rate that was 11th highest in MLB (minimum 750 swings) and contributed to his 129 strikeouts (31.2 K percentage). On the other hand, consider what Happ did when he connected. Among 284 hitters who put at least 200 balls in play, Happ tied for 16th by turning 13.3 percent of those batted balls into barrels — a Statcast™ term indicating an ideal combination of exit velocity and launch angle. Happ’s barrel rate matched those of Freddie Freeman, Paul Goldschmidt and Mike Trout.
Bradley Zimmer, OF, Indians
Before breaking his left hand in early September, Zimmer smashed the Indians’ hardest home run of the year (a 112.2-mph grand slam) and flashed two other top-notch tools. Zimmer, who went 18-for-19 on stolen-base attempts, posted an average sprint speed of 29.9 feet per second on max-effort plays, trailing only Byron Buxton and Billy Hamilton of the 451 players with at least 10 qualifying runs. Of the 28 outfield throws that Statcast™ tracked at 99.5 mph or harder across MLB this year, Zimmer was responsible for eight — including five of 100-plus mph. He also had three of the six hardest-thrown outfield assists, led by a 101.5-mph strike to the plate on June 18 at Minnesota.
Adam Engel, OF, White Sox
The 25-year-old struggled at the plate, but despite playing just 96 games in the field — all but one in center — Engel finished with 15 catches of four or five stars (0-50 percent catch probability) to tie Lorenzo Cain and Michael A. Taylor for sixth among MLB outfielders. While an average outfielder is projected to have caught 85 percent of fly balls hit to Engel, based on their difficulty, the Sox rookie actually hauled in 91 percent. That helped him rack up 16 Outs Above Average to tie American League Gold Glove Award winner Mookie Betts for third in MLB, behind only Buxton (25) and Ender Inciarte (19).
Johan Camargo, SS/3B, Braves
While the highly touted Dansby Swanson struggled for Atlanta in 2017, the switch-hitting Camargo batted .299/.331/.452 in 82 games across multiple positions. Along the way, he produced the two hardest tracked throws on an infield assist this season (93.1 mph and 92.7 mph), and he had two others at 91 mph or harder. Of the 153 infielders who had at least five qualifying throws, Camargo’s average arm strength of 90.9 mph on max-effort plays ranked first.
Rafael Devers, 3B, Red Sox
Despite debuting three months prior to his 21st birthday, Devers more than held his own over 58 games, batting .284/.338/.482 with 10 homers. His hard-hit rate of 44.9 percent ranked eighth of 143 lefties who put at least 150 balls in play, showing that there’s plenty of thunder in his bat. As for Devers’ ability to handle heat, look no further than the game-tying ninth-inning homer he socked at Yankee Stadium on Aug. 13, off a 102.8 mph fastball from Aroldis Chapman. Since pitch tracking began in 2008, no player has homered against a faster pitch.
Rhys Hoskins, 1B/LF, Phillies
Once he debuted on Aug. 10, the 24-year-old went deep 18 times in only 50 games, all of them coming during a 30-game stretch from Aug. 14-Sept. 14. Of the 117 batters who took at least 300 swings from Aug. 10 onward, only Giancarlo Stanton, J.D. Martinez, Josh Donaldson and Judge exceeded Hoskins’ rate of homering on 4.8 percent of his cuts. Hoskins also ranked eighth during that time (minimum 100 batted balls) with a barrel rate of 13.5 percent, and he destroyed pitches to the middle or outer third of the strike zone (.833 slugging percentage).
Yandy Diaz, 3B, Indians
Cleveland teammate Francisco Lindor has raised his average launch angle from 3.8 degrees to 13.7 degrees since 2015, and a similar transformation could work wonders for Diaz. Of 387 batters who put at least 100 balls in play in 2017, the Cuba native ranked seventh in average exit velocity (91.5 mph) and fifth in hard-hit rate (50.8 percent). Yet Diaz also slugged only .327 over 49 games. How? He posted the lowest average launch angle (0 degrees) in that group, as well as the 11th-highest ground-ball rate (58.2 percent).
Brett Phillips, OF, Brewers
The 23-year-old showed a solid bat in his 37-game debut, but his arm is what stood out the most. Take Sept. 14 against the Pirates, when Phillips pulled off a double play by catching a fly ball and then nabbing David Freese at the plate with a 104-mph rocket that stands as the hardest outfield assist of the year and the second hardest ever recorded by Statcast™. Five days later, at Pittsburgh, the Bucs held the potential tying run at third base in the sixth inning as Phillips caught a fly ball and unleashed a 104.7-mph heave toward home. Despite his lack of playing time, Phillips finished with MLB’s three hardest outfield throws of 2017 and four of the top 10 — all faster than 101 mph.
Magneuris Sierra, OF, Cardinals
There is a strong correlation between youth and speed, so it’s no surprise that several first-year players showed off impressive wheels in 2017, including Zimmer, Engel, the Mets’ Amed Rosario, the Padres’ Franchy Cordero, the Astros’ Derek Fisher, the Braves’ Ozzie Albies and the Nationals’ Victor Robles. But while Sierra just missed having enough qualifying runs to appear on Baseball Savant’s standard sprint speed leaderboard, his max-effort average of 29.9 feet per second otherwise would have tied Zimmer for third in MLB. Over just 22 games, the 21-year-old recorded St. Louis’ five fastest home-to-first times on non-bunt singles in ’17, all of them 3.93 seconds or better.