We got another raft of rule changes from MLB for 2024. Some of them are tweaks to the 2023 changes; some are completely new. As usual, details are in short supply, so I’ve tweaked this information out of several places, and some of it is subject to further change.

Pitch Clock

As we know, the 2023 rules imposed a time limit on how long a pitcher may take between pitches. For 2024, the time between pitches with runners on base has been shortened from 20 seconds to 18. (The time between pitches with the bases empty remains at 15 seconds.)

After a dead ball, the pitch clock will start as soon as the pitcher has the ball back (or a new ball), instead of waiting until the pitcher is on the mound.

The First Base Line and the Two-Foot Line

While running to first base, the batter will now be permitted to run anywhere between the two-foot line and the edge of the infield grass, rather than being constrained by the foul line. The MLB press release contains a strange note stating that ballparks will be given a grace period to modify their basepaths to conform to the rule. If this is really the case, then MLB is tacitly admitting that some ballparks have basepaths that don’t conform to the field layout rules in the rule book.

(BTW, I think this is a terrible rule change. The biggest problem is that it gives the batter license to run directly at the first baseman who is trying to cover the base. I predict lots of collisions.)

Mound Visits

The number of mound visits allowed per game is reduced from 5 to 4. Teams still get an additional one at the start of the 9th inning, if they have used them up.

Pitchers Warming Up

When a relief pitcher steps into the field of play with less than two minutes remaining in the between-innings break, the clock will be reset to 2:00 rather than 2:15.

A relief pitcher who goes to the mound (the field mound, not a mound in the bullpen) between innings and warms up is considered to have entered the game. The pitcher must then abide by the three-batter rule. This is to eliminate teams trying to "deke" the other team by sending out a pitcher to warm up, and then replacing that pitcher just before the start of the next inning.

(Caveat: It’s not clear to me if this applies to any game break, or just the between-innings break. The MLB press release is written to imply that it only applies to between-innings breaks. However, it also says "the pitcher must face at least one batter", which makes no sense in that context, since the three-batter rule ensures that the pitcher must face three batters anyway.)