A guide to the obscure, quirky MLB rules that arise in the 2021 postseason

There’s always a chance you’ll see something you’ve never seen before when you watch a baseball game. No matter how much baseball I’ve watched, no matter how broad and deep my knowledge of the game is, there is always more to learn. The intricacies of baseball are astounding and weird, and sometimes it seems like there is an infinite number of them.

A number of baseball’s more obscure rules have come into play in the 2021 postseason games that have taken place so far. Witnessing these strange plays and situations unfold is exciting. Baseball is a sport where the box score doesn’t really reveal anything about the story of the game, and the way one odd rule application can alter the game’s outcome means there is always potential for something unpredictable to occur. Let’s revisit a few of these esoteric postseason plays that had fans, broadcasters and players alike digging into the annals of Major League Baseball’s official rulebook.

Baseball Rule 5.05(a)(8): The rule that cost the Rays the go-ahead run in ALDS Game 3 against the Red Sox

With two outs in the top of the 13th inning of a game that would last more than five hours, Rays outfielder Kevin Kiermaier was at the plate and Yandy Diaz was on first. Kiermaier hit a fly ball off Nick Pivetta to deep right field. Initially, it looked like Kiermaier might have hit a homer. But, the ball sailed over Renfroe’s head and bounced against Fenway Park’s short fence in right field. Renfroe chased after the ball, but couldn’t quite get to it, and the ball deflected off Renfroe’s torso and over the wall, out of his grasp. Had the ball remained in the outfield and not bounced over the low-lying wall, Diaz would have scored easily. However, in lieu of being awarded home — and thus, scoring the go-ahead run — Diaz was sent back to third base and Kiermaier was instructed to take second.

Sudden confusion and murmurs spread throughout the ballpark. A batted ball that bounces over the outfield wall is a ground-rule double, of course, but what happens when the ball bounces over the wall because it ricocheted off the outfielder’s body?

Rule 5.05(a)(8) explains what should happen in this situation: it should be treated as a ground-rule double, so each runner gets two bases. The umpires have no discretion (ability to use subjective judgement) on this type of play. Many Rays fans found this result upsetting, as most would agree this rule is misguided in this particular case. In effect, the rule penalized Kiermaier, who had just managed an extra-base hit, and benefited the Red Sox player who didn’t cleanly field the ball. Below, Jeff Passan details how the rule is applied differently, depending on whether the ball’s deflection off the player’s body was intentional or not.

Baseball Rule 5.09(b): The unusual baserunning call that went against the Astros in ALDS Game 3 against the White Sox

Leading 7-6 in the bottom of the fourth inning, the White Sox had runners on first and third with nobody out when Yasmani Grandal hit a ground ball to first base off of Zack Grienke, who had just entered the game in relief for the Astros. Astros first baseman Yuli Gurriel charged the ball and looked to throw home in an attempt to get Luis Robert out, who was attempting to score from third. Gurriel committed to the throw home, but Grandal, who had begun to run to first base, veered enough inside the foul line that he was running on the grass, rather than the dirt base path surrounding it. Because of where he was running, Grandal blocked Gurriel’s throwing lane to the plate, and Gurriel’s throw home deflected off Grandal’s shoulder and rolled to the backstop, allowing the run to score with everybody safe.

Why wasn’t Grandal called out for either a) running out of the baseline, or b) physically interfering with Gurriel’s throw to home?

According to the MLB rule book, any runner is out when they run more than three feet away from their baseline to avoid being tagged, or when they intentionally interfere with a thrown ball or hinder a fielder attempting to field a batted ball. While Grandal looked as if he was outside the baseline, no one was attempting to tag him. The first and most important thing to know about the so-called base path is that there is no base path established unless a play is being made on a runner (in Grandal’s case this would be a play at first). Because Gurriel threw home, no one was attempting to put a tag on Grandal.

The base path is established when a fielder with the ball attempts to tag a runner. While the rule is commonly conveyed as simply being “outside the baseline,” this rule only applies to situations when a fielder is attempting to tag the runner, or when a play is being made at the base to which the runner is running. In essence, if no play is being made on the runner, he can establish whatever base path he wants.

The other part of the umpire’s call hinged on whether Grandal’s path — which appeared to veer into Gurriel’s throw — could be considered intentional interference. Interference calls are at an umpire’s discretion. The umpires huddled and ruled that Grandal had not intentionally interfered with Gurriel’s throw, so Grandal was ruled to be safe at first base.

Braves vs. Brewers NLDS Game 4: Why Luis Urías’ questionable catch was not a reviewable play

Ever since MLB first released its Replay Review Regulations in 2014, the question of what is and isn’t considered reviewable has been a point of contention. While certain plays — pitchers intentionally throwing at batters or certain interference/obstruction calls — are left to umpires’ discretion and are excluded from replay eligibility, there are other plays where the reasoning underlying their ineligibility to be reviewed is less clear. Fly balls in the infield, for instance.

In the bottom of the fourth inning during the Brewers-Braves NLDS Game 4, Brewers third baseman Luis Urias made what appeared to be a phenomenal catch on Adam Duvall’s foul pop up after it ricocheted off Brewers catcher Omar Narvaez. Slow-motion replays on the broadcast showed that the ball might have hit the ground before Urías secured it in his glove, so the umpires convened to review the catch. Here’s a closer look.

The umpires immediately came back and the call that Urias made the catch stood. Even though replay seemed to show that the ball hit the ground before Urias caught it, the play isn’t reviewable, so the question of whether or not Urias made a legal catch is moot. MLB’s Replay Review rules specify the following calls are reviewable via replay:

Catch plays in the outfield: An umpire’s decision whether a fielder caught a fly ball or a line drive in flight in the outfield before it hit the ground is reviewable, but fly balls or line drives fielded by a defensive player in the infield is not eligible for review.

Even if replays showed Urias didn’t catch the ball before it hit the dirt, the play was made by the catcher Narvaez, who is an infielder. That is to say, even if the umpire’s call was wrong — and it appeared to be — the call is not reviewable and the incorrect call that the catch was made had to stand. No matter how badly Braves manager Brian Snitker wanted to challenge the play, infield catch calls are not considered reviewable.

If the point of replay is to get the call right, this play makes a strong argument that MLB needs to revise rules governing replay challenges.