The impact on the environment – ​​part two

Translated by Marco Gámez

We already discussed the universal designated hitter and the ghost runner rule in Part 1 of this review on the rule changes.

Stolen bases

The shot clock came with the familiar provision that attempts to surprise runners were limited to two “gifts” to control those circulating players. After that, a third down attempt must end with the runner out or he receives the next base as a reward. Immediately, the runners on the bases began to salivate, and the saliva was justified. In 2022, the average MLB team stole 0.51 bases per game (and was caught 0.17 times). In 2023, the theft rate jumped to 0.72 and remained level in 2024 at 0.74. Out rates on attempted steals increased slightly (0.18 and 0.20), but that means both attempt and success rates increased overall.

The value of a stolen base has gone down a bit in recent years.

In an environment where teams rely more on using power to score runs (something the modern game certainly leans toward) it becomes less important to be on second base than first because with a home run you’ll score from either base, but The average successful stolen base is worth about 0.17 runs while the average out attempted steal reduces about 0.44 runs’ expected runs on a team’s account. The reason being caught in an attempted steal (CS) is so much worse than a successful steal is because it represents both an out and the loss of a runner.

If the average number of stolen bases per game has increased by 0.22, and if each one equals 0.17 runs, that’s 0.0374 additional runs per game, although that should be tempered slightly with 0.02 outs for being caught stealing per game, each equivalent to – 0.44 runs, for a total of -0.0088 runs. It all adds up to 0.0286 and we can round it to +0.03 scores.

Prohibition of defensive rearrangements

This is more difficult to analyze because the defensive rearrangement was complicated. It was difficult to know that was being done, even when it was legal. It reduced the chances of ground balls going through the infield, but it seemed to have some side effects. There were more walks when the adjustment was applied and more line drives that negated most, if not all, of the impact the strategy had. It also depended a lot on the batsman’s hand. The rearrangement “worked” for left-handed hitters, although not for right-handed hitters.

One thing that is clear is that the ban did not have the effect that the League expected. In theory, banning the adjustment should have increased the circuit’s overall BABIP, but it didn’t. As late as 2017, the League’s BABIP was at .300, a number that had remained remarkably steady over the years. But starting in 2018, it began to decline until reaching .290 in 2022. In 2023, the first year of the rearrangement ban, it recovered to .297, but this year it landed at .291.

Interestingly, the result is most evident in the ground balls hit to the batter’s strong side that the fit was so famous for capturing. Here’s BABIP on ground balls:

On the face of it, the adjustment ban did exactly what it was supposed to do. It gave late ground balls—particularly from left-handed hitters—a better chance of getting over the frame and becoming hits. The rearrangement ban was doing its part for BABIP. Why didn’t the BABIP increase again throughout the League?

The answer is fly balls, and prohibiting rearrangements could, counterintuitively, have caused the problem. The fly ball rate in the MLB has been increasing little by little in recent years. Fly balls are more valuable than ground balls, mainly because some fly balls go over the fence. And if you’re going to hit a fly ball, you can also try to pull the ball. Late fly balls are much more likely to leave the ballpark. But if you’re trying to pull, you’re going to mess up some and hit some pulled ground balls. The defensive rearrangement was the perfect defense for those pulled ground balls, but the prohibition of the adjustment had reversed cause and effect. The assumption was that the batsmen were more interested in pulling all the balls. But they weren’t. The pulled ground balls were the errors. Hitters were trying to hit home runs, because they’re really valuable, and banning the adjustment did nothing to change that preference. In a scoring quirk, BABIP does not count home runs because they are not “in play” for the defense to make a play. Hitters out of the park are easier to turn into outs than ground balls. As a result, the League-wide BABIP fell.

With the defensive adjustment prohibited, hitters had even more freedom to try to hit everything out of the park. If they made a mistake and hit a ground ball instead, there was less of an obstacle for it to turn into a fluke that would at least get them to first base.

When defensive rearranging was banned, it was the default defense against left-handed hitters. The defensive adjustment reduced the singles rate, compared to what those same hitters did without the defensive adjustment in the infield. For left-handed batters, scoring decreased by .009 runs per appearance before rearrangement using a linear weights approach. For right-handed hitters, their performance increased by .008 runs per appearance due to the defensive rearrangement. In general, an appearance against the defensive rearrangement was worth around -0.002. This leaves us in a quagmire to navigate. I can calculate the effect of the infield rearrangement in 2022, its last year of operation. In that year, one-third of all plate appearances came before the adjustment and the average team had 37.5 plate appearances. That’s 12.5 plate appearances versus team adjustment, where the effect is 0.002 runs overall for a total of 0.025 runs per game that the defensive rearrangement avoided. The prohibition of defensive rearrangement probably put them back on the scoreboard.

But is that the true effect of the rule? Over time, the defensive rearrangements against right-handers (which were costing teams runs) would likely have faded, but against left-handers (who were getting older) would have only become more frequent. Naturally, the defensive realignment would have become more toxic to run scoring if it had been allowed to continue.

Again then, if banning rearrangement made players more comfortable hitting for the fences, it would be a strategy that is more efficient for scoring runs overall. That might have indirectly increased run scoring, but should we attribute that to the adjustment ban or the fact that teams have consciously embraced the dark side of the modern power approach?

Let’s add all these numbers:

• .16 runs per BD rule

• .04 runs per ghost runner rule

• .03 runs because of the way the pitch clock increased stolen bases

• .03 (approximately) runs due to the prohibition of defensive rearrangements

The net result is 0.26 runs per game that the rule changes have added. There has to be some “rough” factor there, but there is always something “rough” when we do this type of analysis. The new rules are increasing scoring and that quarter run is noteworthy. On Friday, I asked them to note that most of the game’s modern history has been played within the limits of between four and five runs per game. This is a quarter of that differential. We must at least recognize it in our analyses. The new rules are artificially inflating the run-scoring environment.

But with all that said, the actual results MLB teams have gotten have gone in the other direction. The designated hitter was temporarily installed in the National League for the 2020 season, which theoretically should have increased the run environment, runs per game fell from 4.83 to 4.65. In 2021, the National League returned to pitchers hitting (4.53) and in 2022 made the designated hitter permanent and MLB saw another decline from 4.53 runs per game to 4.28.

There are other forces acting on the racing environment in baseball. The use of pitchers has been revolutionized in the MLB, with starters pitching five innings and short relievers covering the rest of the way. Speed ​​increases, spin increases, movement increases (and injuries increase). Batters swing for the fences. The outfield has become a giant glove as teams have improved the placement of their players in the 7, 8 and 9 positions. The ball… something strange has been happening with the ball during the last decade. And the old randomness is always lurking. As MLB tries to shape the game on the field, it’s important to know where the levers are and how powerful they are. Clearly, the forces around strategy and whatever is happening with the ball are more powerful than those around the rules.