Pete Alonso has arrived on the MLB scene at a weird time, but has made a splash in a phenomenal rookie season, and a follow-on COVID-shortened 2020.
Alonso’s rookie season was one of the best in team history, as he became the first Mets hitter to win Rookie of the Year honors since Darryl Strawberry did it in 1983. Alonso came up through the Mets’ farm system with a reputation as a free-swinging slugger.
Alonso delivered an exceptional performance in 2019, posting a 4.8 fWAR and 148 wRC+, highlighted by a rookie-record-setting 53 home runs. The 53 homers bested the previous rookie record for home runs set by cross-town rival Aaron Judge in 2017 (Judge hit 52 in his rookie season).
Earlier this week Alonso cranked his 70th home run in just his 220th game, setting yet another MLB record. It’s not a surprise, as last season he managed 16 home runs in just 57 games (a mid-40 home run pace over the course of a full season).
Alonso’s post absolutely crushes fastballs, as 40 of his 70 career home runs have come off fourseamers and sinkers. To-date, the right handed power hitter has not shown much of a platoon split at all, as he’s batting .292 for his career against right handed pitchers, and has teed off on RHP’s fastballs 28 times
In 221 games, it’s pretty obvious that Alonso can send nearly any fastball out of the yard quicker than it arrives at the plate. Where he’s struggled most has been on offspeed pitches, particularly sliders and changeups.
Alonso is somewhat of a free swinger, but that free swinging comes more often against offspeed pitches and to a lesser result. He has a 12 percent whiff rate against four seam fastballs, compared to a 21 percent whiff rate against changes and sliders (again, the handedness of the pitcher doesn’t change these numbers).
In a division that includes hard throwing aces such as Max Scherzer, Stephen Strasburg, Chad Sobotka, among others, it will be interesting to see how teams adjust to Alonso in a full season, where teams see their division rivals nearly 20 times.
Alonso isn’t much of a help in the field and would be a major beneficiary of a universal designated hitter, but provided he can keep up this production on offense, it hardly matters. If teams get wise that they can offer more high-leverage off-speed, the K numbers may increase while the homers and batting average suffers.