MLB is tinkering. They are trying to make the game more exciting. One rule that could achieve this is an increase in the size of the bases. First, second, and third base have been a 15 inch square for the entire history of the game. MLB is testing out 18 inches bases in the Arizona Fall League. This follows a similar test at the Triple-A level during the 2021 season. The larger base will theoretically have a few benefits.
The bigger base will reduce the distance between first and second base by 4.5 inches. It is 4.5 rather than 6 because second base is centered on the corner of the diamond rather than inside the diamond like first and second. You can see that in the diagram above. I previously wrote about how moving second base within the diamond would increase extra-base hits and stolen bases. That change would be even more extreme, decreasing the distance between first and second by 7.5 inches. Analysis of the bigger base in 2021 showed that stolen base attempts and success rates were higher.
Another benefit of larger bases should be more infield hits. The larger base not only shortens the distance from home to first, it also shortens the distance that an infielder throws the ball. Given the…
