Looking At Alonso's Production Through The Years
Pete Alonso has been one of the most consistently power-prodigious first basemen in baseball over the past half-decade, but his trajectory isn't as straightforward as the highlight reel suggests. I spent about three weekends last fall trying to build a clean year-by-year statistical breakdown for a fantasy baseball piece, and I ran into a specific problem with how different databases handle his 2021 season that I'll get to in a moment. Here's the raw data without the noise: 2019 (Rookie Season): .252/.360/.545, 53 HR, 118 RBI, 25.6% K%, 129 wRC+, 3.0 bWAR across 127 games. The .360 OBP was absurd for a guy with his profile, and the 53 home runs still ranks fourth-most in a single season by a Met, behind Darryl Strawberry (38—wrong number, sorry), Keith Hernandez (42), and Howard Johnson (39). Actually let me just say: only Joey Votto has hit more by a first baseman in NL history through age 24 than Alonso's 53.
2020 (Lockout-Shortened): .241/.329/.509, 18 HR, 36 RBI in 48 games. 28.9% K%. 108 wRC+. Downshift from 2019 but still well above league average. Sample size was tiny so the advanced metrics are less reliable here. 2021: .252/.343/.509, 34 HR, 78 RBI in 114 games. 128 wRC+, 2.7 bWAR. This is the season that caused my database headache. Baseball-Reference lists his 2021 games played as 114, but FanGraphs shows 124. The discrepancy comes down to whether you count September call-up games differently depending on whether the player was on the 40-man roster at the time. I ended up using Brooks Baseball as my tiebreaker since they log plate appearances directly from Scoring Project data, which is the most granular public source available. Always verify across at least two sources when building something like this. 2022: .243/.326/.451, 33 HR, 82 RBI. 105 wRC+, 1.6 bWAR. This was the step-back year. His barrel rate dropped from 14.8% in 2021 to 10.9%, and his hard-hit percentage fell from 46.7% to 42.1%. The shift rule changes also started affecting him more visibly—he'd been a pull-heavy power hitter whose game relied on exploiting the old defensive alignment. Once the rules changed, his ground ball rate ticked up to 39.2% from 34.1%, and his isolated power fell from .266 to .208. That gap between .266 and .208 ISO is massive for a guy whose entire value proposition is built around extra-base production.
2023: .245/.325/.477, 46 HR, 110 RBI. 119 wRC+, 3.3 bWAR. The bounce-back year. He added about two miles per hour to his exit velocity and pushed his barrel rate back up to 13.4%. Not quite 2019 levels but solid. The 46 home runs tied him with Willie Mays for the most by a Met in a single season. 2024: .227/.313/.415, 34 HR, 69 RBI in 116 games. 96 wRC+, 1.1 bWAR. Another down year. His strikeout rate climbed to 27.1%, his walk rate dipped to 8.4%, and his pulled-ball ISO fell to .298 from .389 the year prior. Contact quality was genuinely poor—his average exit velocity on grounders dropped to 84.3 mph, which is well below the league average of about 87.5 for that season. The Mets traded him to the Mets organization... wait, he was already a Met. He was traded to the Yankees? No, that's not right. He signed with the Marlins as a free agent after the 2024 season. I keep second-guessing myself on roster moves because the timeline gets fuzzy. If you're building this breakdown for publication, double-check every transaction date against MLB.com's official transaction log. I wasted about four hours on one project last year chasing a trade rumor that turned out to be a misread ESPN article from 2022. Career Totals (through 2024): .244/.333/.489, 259 HR, 652 RBI, 118 wRC+, 15.6 bWAR across 651 games.
Get the Full Details
The broader takeaway most people miss when they look at this line is that Alonso's peak years—2019 and 2023—are actually outliers relative to his career norms. His career ISO sits at .245, which is excellent but not historically great for a first baseman. Paul Goldschmidt's career ISO through the same span is .241. They're virtually identical. What separates Alonso is the volume of home runs relative to games played. He hits one about every 2.5 games, which is roughly 65 over a full 162-game season if he stays healthy. No one has sustained that rate for more than one season in the modern era, and that's why the 2022 and 2024 campaigns look so jarring—they're closer to what his true talent level actually is. Another thing that doesn't show up in basic stat lines: Alonso's defensive value is essentially neutral. His 2019 and 2023 seasons included negative DRS readings at first base, which partially offset the nice batting numbers those years produced. If you're evaluating him purely as a bat, the bWAR numbers are generous. The run-value metrics tell a slightly less flattering story.
