Bryce Harper and Mike Trout turned in epic seasons while taking home Rookie of the Year Honors. In addition to their swift defense and base running savvy, Harper (whose 22 HR trailed only Tony Conigliaro among all teenage hitters) and Trout (whose 171 OPS+ was highest ever for a player qualifying for the batting title during his age-20 season) were historically dangerous in the batter's box. But the two stars destined to be compared to each other for decades to come began their at-bats in markedly different ways. Harper was ultra-aggressive on the first pitch. Trout, by contrast, rarely took the lumber off his shoulder in 0-0 counts.
Check out Harper and Trout's swing rates by pitch location in 0-0 counts:
Harper's first-pitch swing rate by pitch location
Trout' first-pitch swing rate by pitch location
Harper took one of his hellacious cuts about 41% of the time in first-pitch counts, dwarfing the 26% major league average. The only qualified hitters with a higher first-pitch swing rate were Josh Hamilton, Ian Desmond, B.J. Upton, Freddie Freeman, Yadier Molina, Delmon Young, Danny Espinosa and Chris Davis. Harper's aggression paid off, as he slugged .659 on the first pitch (.579 MLB average).
Trout swung just under 10% of the time in first-pitch situations. Kevin Youkilis, Martin Prado, Joe Mauer, Dustin Pedroia and J.J. Hardy were the only batters with a more passive approach on the first pitch. While Harper chased 24% of pitches thrown out of the strike zone in 0-0 counts, Trout showed Zen-like patience by going after only 5% of first-pitch offerings (14% MLB average).
Two all-time great rookies, two totally different (and effective) ways of beginning ABs. Harper embraced his inner Josh Hamilton, lunging at first pitches and tallying lots of extra-base knocks. Trout channeled Rickey Henderson, laying off would-be balls and later doing damage in hitter's counts. Sorry, pitchers: whether these guys swing at the first pitch or not, you really don't stand a chance.