When Russell Martin’s throw back to the pitcher hit Shin-Soo Choo, and Rougned Odor raced home to score the go-ahead run, the pages of baseball’s rule book fluttered open across America and Canada. A stunned silence in the park hid the grinding of gears behind the masks, and in baseball’s offices — was that strange, strange play… legal?

Yes, it turns out. To the consternation of the fans, who began to litter the field with debris. Twitter, the announcers, the fans — it was bedlam.

But investigating the rules that led to this play, and any rules that could clean up a play like this in the future, brings us to the never-ending unintended consequences that come with any alteration of the rule book.

First, the play.

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Then, the rule that suggests that, yes, the ball is live and the run scores.

6.03(a)(6.06)(3) (a) (6.06) A batter is out for illegal action when:

(3) He interferes with the catcher’s fielding or throwing by stepping out of the batter’s box or making any other movement that hinders the catcher’s play at home base.

Choo did nothing illegal because he was in the box and the umpire never ruled that he interfered on purpose. Any time out or sign that the ball was dead would actually be erroneous — the only other call that could have happened, it seems, is calling the batter out for interference.

Baseball also distributed an explanation of the rule to writers at the game, and it specifically states that “if the batter is standing in the batter’s box and he or his bat is struck by the catcher’s throw back to the pitcher (or throw in attempting to retire a runner) and, in the umpire’s judgement, there is no intent on the part of the batter to interfere with the throw, the ball is alive and in play.”

Calling the batter out here for intention would go too far. Shin-Soo Choo was just setting up in the box. He was just adjusting his glove and was as surprised as any that Martin hit him. Even Martin, reflecting after the game, admitted that he didn’t “really know what the rule was” and that Choo “was in the box.”

Wait, why was Choo in the box? Because of another (new) rule. Because of unintended consequences. Here’s the rule that kept Choo in the box.

(4) (6.02(d)) THE BATTER’S BOX RULE.

(A) The batter shall keep at least one foot in the batter’s box throughout the batter’s time at bat, unless one of the following exceptions applies, in which case the batter may leave the batter’s box but not the dirt area surrounding home plate:

(i) The batter swings at a pitch;

(ii) The batter is forced out of the batter’s box by a pitch;

(iii) A member of either team requests and is granted “Time”;

(iv) A defensive player attempts a play on a run- ner at any base;

(v) The batter feints a bunt;

(vi) A wild pitch or passed ball occurs;

(vii) The pitcher leaves the dirt area of the pitching mound after receiving the ball; or

(viii) The catcher leaves the catcher’s box to give defensive signals.

This rule was enacted this year. Choo was following the new rules. Under the old rules, he probably would have been adjusting his gloves outside of the box, as was pointed out to me on twitter. But the new rule kept him in the box, closer to Martin’s throw.

A rule put in place to improve the pace of play indirectly led to an 18 minute delay.

So should we fix this rare play with a rule? I think the words spent on the way in here suggest no, but let’s pretend that the Blue Jays lost the game on this play and that we have a country full of people who are currently apoplectic about the fact that this ball was live. I don’t think anyone wants to see batters holding their bats across the plate hoping the catcher hits it on his throw back to the mound, so perhaps a new rule could help reduce the chance that this unintended consequence determines the outcome of a game.

Let’s say that any ball that hits the batter on the way to the pitcher is dead. We already have a rule that can provide a framework. This rule tells us that the ball is dead if the backswing of the batter unintentionally hits the catcher.

6.03(a)(6.06)(3)(c) If a batter strikes at a ball and misses and swings so hard he carries the bat all the way around and, in the umpire’s judgment, unintentionally hits the catcher or the ball in back of him on the backswing, it shall be called a strike only (not interfer- ence). The ball will be dead, however, and no runner shall advance on the play.

Easy enough to use that sort of language to say that the ball is dead if the catcher’s throw unintentionally hits the batter on the way back to the pitcher. Easy enough, except that we’ve just changed the judgment call from the batter (was he blocking intentionally) to the catcher (was he throwing intentionally).

And, if you were a savvy catcher with an axe to grind with a specific batter, it might be easy enough to wing a throw right into the batter, shrug, and say “ball’s dead.”

We often call for new rules when we’re faced with terrible injuries, or game-turning plays that just don’t seem right. It’s hard not to have sympathy for a Jays fan watching their season hang in the balance because of a strange thing that happened that pretty much nobody has seen before. If it had changed the game, we might actually be talking about a rule change. It’s certainly happening in other phases of the game.

But, as always, we have to carefully consider all the unintended consequences to any alteration of the rule book. In this case, the play was so bizarre and rare that it seems unlikely that the best way forward is to tempt those possible outcomes — whatever they are. Maybe we should just revel in the weirdness of that moment and move on without legislation.

Given that MLB is now requiring batters to stay in the box, however, it’s probably worth thinking through whether that dynamic impacts the viability of other rules already on the books. A new rule, or even a modified rule, is not always the right reaction, but given that baseball made a significant change to batter placement between pitches last year, it might be time to evaluate the effects of that decision this winter.