New York Mets: Pete Alonso underperformed against fastballs in 2020

New York Mets, Pete Alonso

The New York Mets, despite failing to qualify to the playoffs, boasted one of the best offensive units in the league. They were among the leaders in wRC+ and their lineup didn’t have too much trouble producing runs.

However, the sophomore season wasn’t so smooth for first baseman Pete Alonso. The Mets’ slugger was the Rookie of the Year in the National League in 2019, and he set a record for most home runs for a first-year player with 53.

While he hit homers at a similar pace this season (16 in 57 games), his overall production fell off a cliff. In 2019, he slashed .260/.358/.583 with a .384 wOBA and a 143 wRC+, but this year, he was at .231/.326/.490 with a .342 wOBA and a 119 wRC+.

The New York Mets’ star had a horrible first July/August, with .213/.333/.385, a .309 wOBA and a 97 wRC+. Thankfully, he improved in September (.256/.316/.640, .391 wOBA, 151 wRC+) and was more like the player we know he is.

So, why did he struggle in 2020? His 90.7 mph 2019 average exit velocity was similar to that of this year, 90.2 mph. His BB% and K% were also similar (10.4 BB% in 2019, 10.0 in 2020; 26.4 K% in 2019, 25.0 K% this year.) So what changed?

The Mets are hoping it was just small sample size noise

Alonso, who is still among the New York Mets’ most important players for the future, performed at a similar level against breaking balls in 2019 and 2020. Last year, he had a .292 wOBA against sliders and curveballs, and while the number went down to .278 in 2020, it isn’t a significant dropoff.

However, if we examine his numbers against fastballs, we see a significant collapse. His wOBA against the pitch was .358 in 2020, a rather mediocre mark considering his abilities and the fact that he finished with a .438 wOBA against heaters in 2019. Alonso slugged .513 against them in 2020, a far cry off the .669 mark of 2019.

His expected batting average versus fastballs was .237 this season. It was .286 last year.

It could be small sample size noise. It could a timing issue. Either way, the Mets will be expecting Alonso to make the proper adjustments and start punishing fastballs again in 2021.