The effect of new bases size on the New York Mets

In a set of rules that MLB will enforce by 2023, the league has agreed to change the size of bases from 15 inches to 18 inches. So what? What relevance does this have? How does it affect or benefit the New York Mets?

It's simple, now the distance of the second base from the first and third is 4.5 inches closer. With this new rule and the limitation that the new pitching clock imposes on pickoff throw attempts, the world of base stealing rises from the ashes.

What does this mean for the Mets?

Despite having seven position players last year with above-average sprint speed, the team finished 23rd in all baseball in stolen bases. This year they have added an average speedy player in the name of Tommy Pham and Tim Locastro, #7 in all of MLB in this category.

We should expect a more aggressive approach from the Mets on the bases, especially from Marte and Lindor who led the team last year in SB but also from Locastro and Nimmo. Being aggressive on the base paths is not just a matter of individual performance but an opportunity to increase your expected number of runs, so the more bases reached, the greater the probability of winning.

Fangraphs created a matrix to measure this, where they calculate the expected value (runs) at the different moments and events in one inning, that is, the expected number of runs in every base depending on the number of runners and outs. By this criteria, a runner in 1B with no outs generates a run expectancy of 0.831 and in 2B a 1.068. So, stealing 2B with no outs increases your expected number of runs in 0.237.

Which Mets player will benefit the most?

Believe it or not, the fastest regular player in the Mets lineup is not Starling Marte but Brandon Nimmo. He had a sprint speed (ft/sec) of 28.7 located in the top 16% of the league. That's pretty incredible if you take into account that he only stole three bases last season.

Whatever the reason Nimmo didn't try to steal more bases last year, be it health precaution or the coach's decision, expect a significant increase in 2023. And, with more stealing bases from him plus his high on-base percentage, he can give the team better run-scoring opportunities early in games and increase the team's chance of winning.

In conclusion, this new rule, given the composition of this team, offers an opportunity for the Mets to be more aggressive on the basepaths and create more runs with it. However, other factors such as the type of pitches (fastball, breaking balls, and off-speed pitches) and the opponent catcher's arm strength could play into game decisions from the runner's perspective. The latter is relevant to the Mets given that the NL East Division boasts two of the top 5 catchers in the Pop Time 2B stat (time to release the ball plus arm strength).