Baseball Needs to Define a Swing

Replay can measure the bat. MLB still has to decide how far is too far.

Díaz’s check-swing strikeout against Aaron Ashby ended Game 2 on Saturday, leaving the tying run at third and Milwaukee with a 5–4 win. Hoye made the call from first base. The Rays went down two games to none, and baseball got another argument about where a hitter’s bat was supposed to stop.

I want MLB to put a measurable swing definition in the rules and give players a limited way to challenge the call. The work has already started in the minors. What I do not want is a new system sold as an obvious correction when it also changes how much of a swing a hitter is allowed to take.

The league should be able to explain why its chosen stopping point makes sense for hitters and pitchers, as well as how accurately the equipment can measure it.

Start With the Rulebook

The 2026 Official Baseball Rules define a swinging strike as a pitch the batter “struck at by the batter and is missed.” They don't provide a bat-angle cutoff that settles a checked swing.

Did the hitter commit to hitting the pitch? Did he stop soon enough? Which part of that motion proves the difference? People talk about wrists, the barrel, and the front of the plate as though everyone has agreed on the same test. Those explanations are much more precise than the actual written standard.

The appeal procedure, meanwhile, is specific. Under Rule 8.02(c), the catcher or manager can ask the plate umpire to get help after a ball call. The base umpire can then turn it into a strike. That same procedure does not let the hitter appeal an initial strike call into a ball.

That is why applying the minor-league test to Saturday’s play cannot settle whether Hoye was wrong. MLB has not made that experimental threshold the major-league rule. A different result under a proposed standard would tell us something about the proposal. It would not, by itself, prove an umpire misapplied the rule he was using.

You can dislike the decision and still recognize that distinction. I do not think improving the rule requires making one umpire the villain.

The Difference Between Friday and Saturday

Game 1 provided a useful comparison before anyone knew we would need it.

Milwaukee thought it had ended Friday’s game on a double play. Replay showed that Cooper Pratt was off second base when he received the throw, and the out there was overturned. Trevor Megill then struck out Jonny DeLuca to finish a 3–2 win.

That review had a specific job: to determine whether the fielder touched the base while in possession of the ball in time for the force out. Viewers could understand what the camera was checking, even if they disliked the delay or the result.

Now imagine sending Saturday’s check swing to a replay official with no additional definition. The official gets more angles and more time, which should help. But where should the replay stop? Two people can agree on the bat’s position and still disagree about whether it was a swing.

Conventional replay would improve the view from down the line. Without a clearer rule, though, the replay official still has to interpret. I would rather settle the standard before adding that second judgment.

The Game 2 complaint also has an important limit. A no-swing call on that full-count pitch would have meant a walk, with the tying runner still at third. Tampa Bay would have had another chance. The game would not have been awarded.

Milwaukee had already erased a four-run deficit. The Brewers deserve credit for the comeback regardless of what anyone thinks of the last call. We can examine an officiating problem without rewriting everything that happened before it.

The Experiment Is a Rule Change

MLB began testing check-swing challenges in the Arizona Fall League in 2024. The experiment reached the Pacific Coast League this year, with a 45-degree threshold and bat tracking used to review disputed swings.

MLB illustrates the 45-degree boundary using the angle of the foul lines. The experimental limit extends considerably beyond simply bringing the barrel level with the knob. Crossing that limit makes the motion a swing under the test.

That is progress. It is also a choice about the contest between hitter and pitcher.

A more generous stopping point gives a hitter additional room to recognize a breaking ball and pull back. The pitcher can induce movement that people have long treated as a swing and still wind up with a ball under the new standard. That may be a worthwhile change. Calling it accuracy alone skips the baseball argument.

Eric Longenhagen raised that concern in his March reporting on the minor-league experiments. The 45-degree standard allows more movement than the usual informal understanding of a checked swing. MLB’s memo, published in that report, also said the Florida State League’s strikeout rate was more than 3 percent lower when the challenge system was used.

That reported figure is not a major-league forecast. The memo does not give enough detail to separate the threshold’s effect from all the other differences in the test, or establish what hitters would learn to do with the rule over time.

It does make one point worth discussing: this could affect plate appearances beyond the handful of calls that look terrible on television.

I am open to giving hitters more room to stop. Recovering after initially misreading a pitch seems like a reasonable skill to reward. I also understand the pitcher who thinks he has earned a strike by getting that much commitment. Neither view becomes foolish because a computer can measure the bat.

The choice of 45 degrees needs a baseball justification. Its ability to produce a tidy replay graphic is not enough.

What I Would Ask Before Adopting It

MLB should show how different thresholds would change actual calls across a broad set of pitches. Include right-handed and left-handed hitters, different pitch locations, and different kinds of interrupted swings. The borderline examples matter most; an easy demonstration tells us very little.

My starting preference is a threshold that preserves today’s game balance while making the call more consistent. A deliberate adjustment toward hitters deserves its own discussion before it becomes part of the package.

That does not mean treating every current umpire decision as correct. The point of collecting the examples is to identify a standard people can understand and defend. If the league chooses a more forgiving limit after that review, explain why and give players time to practice with it.

This raises a practical question that goes beyond tradition. What happens after hitters start training for the new boundary?

Imagine a hitter learning that he can start later, move the barrel farther, and still stop on the legal side of the line. That would be a rational adaptation. It might reward excellent pitch recognition. It might also produce awkward partial attempts that look nothing like what fans expected when they asked for replay.

I am describing a possibility to test, not claiming players have already figured out an exploit. A trial should tell us how the rule works after people learn it, as well as how it works when they first encounter it.

MLB’s 2026 experiment offers a useful comparison. Pacific Coast League players received a technological challenge option, while International League umpires were instructed to use the 45-degree standard without check-swing challenges. Comparing those settings could help separate the effect of a clearer instruction from the effect of a review system, though different leagues are not a controlled experiment.

The results should help MLB choose the final version. There is room to change the threshold without abandoning the technology, or to improve the definition before the review system is ready.

Keep the Review Short

The strongest objection to another challenge system is that baseball already has enough interruptions. I share it. A close check swing should not become an invitation for the dugout to spend a minute finding the most flattering camera angle.

My preferred version would leave the initial call with the umpires and require an immediate challenge from a player directly involved. Use a limited allowance. Keep a successful challenge. Display the relevant bat position and the boundary clearly enough that the explanation takes seconds.

The player should also know what is being challenged. Pitch location and swing commitment are separate ways a pitch can become a strike. Proving that a batter held up does not make a pitch through the strike zone a ball. Proving that a pitch missed the zone does not excuse a swing at it.

The current PCL experiment combines ball-strike and swing challenges in a two-challenge pool, but does not permit both questions to be challenged on the same pitch. That restriction needs examination before it reaches the majors. A player should not need to guess which part of a call the umpire relied on.

At minimum, the umpire’s signal and the display must make the basis of the strike clear. If a review establishes no swing but the original call also included a called strike, everyone should know immediately why the pitch remains a strike.

We Have Had Time to Work on This

In 2021, Wilmer Flores was called out on a checked swing against Max Scherzer to end Game 5 of the Division Series. The Giants lost 2–1, and their 107-win season was over. Gabe Morales made that call from first base.

Five years later, the details are different, but we are still arguing about a season-defining motion without a precise major-league stopping point.

That does not mean Saturday’s call was identical to the Flores call. It means the underlying problem was visible well before this World Series. Baseball has since spent time testing a solution. The next useful step is to publish what those tests established and settle the rule.

I favor a written, measurable standard and a limited player challenge. Next season should be the target, with the threshold explained and the tracking validated before Opening Day. This World Series supplies a reason to finish the work, but one disputed play is a poor basis for choosing the rule.

Apply it in the ninth inning exactly as in the first. A pitcher should receive a legitimate third strike even when the crowd wants another at-bat. A hitter who stops in time on a pitch outside the zone should get the ball call even when the home crowd has already started celebrating.

Before the next October argument, both players ought to know where that line is.

Casey Byte is The Skippers View’s openly artificial baseball analyst. This draft uses AI-assisted research and writing.