“We don’t understand the infield fly rule, either.”

That little joke, likely the doing of some PR person trying futilely to humanize the bio section on the MLB’s Twitter account, was perhaps a little too accurate on Friday night, when obscure infield fly rule was invoked controversially at a crucial moment of a wild card, winner-takes-all playoff game between the Atlanta Braves and St. Louis Cardinals. Likely aware of the firestorm on Twitter (and the literal shower of trash raining down on Turner Field), some poor social media intern flew to the account and removed the now-mocking joke in the bio. Then Bud Selig probably personally fired that PR guy or gal who put that quip up in the first place for not being omniscient.

But, seriously, the infield fly rule? During a playoff game? I’ve probably watched thousands of innings of baseball in my lifetime, and I’ve never seen the infield fly rule make a difference in the outcome of a game. I knew it was in the rulebook somewhere, but I couldn’t give you a solid explanation if you asked. In fact, you may be wondering what it is right now. And even after reading up this weekend, I’m not going to try to explain, so let the MLB rulebook itself take it away:

“An INFIELD FLY is a fair fly ball (not including a line drive nor an attempted bunt) which can be caught by an infielder with ordinary effort, when first and second, or first, second and third bases are occupied, before two are out. The pitcher, catcher and any outfielder who stations himself in the infield on the play shall be considered infielders for the purpose of this rule.”

Basically, once an infield fly is called, the batter is declared out whether or not the ball is caught. It’s technically designed to prevent infielders from purposely dropping pop ups to turn easy double plays in force-out situations.

Well, in Atlanta on Friday night, the Cardinal fielders couldn’t come down with a shallow fly to left field. The Braves were down by three and the dropped fly ball would have ordinarily loaded the bases with only one out. Instead, the infield fly rule meant that they had runners on second and third with two outs, a big difference in the most crucial inning of the game. And the Braves certainly didn’t think the ball was in the infield, nor did they believe it could have been caught with ordinary effort — hence the trash on the field that led to a nearly 20 minute delay.

Of course, this all happened during the biggest game of the year at the time — the second of the new wild card playoff games introduced by MLB this year. Some think adding the one-game playoffs enhances competitiveness and makes the regular season more important; others, like now-retired Braves star Chipper Jones, predicted the chaos that would ensue. On September 21, the Atlanta Journal-Constitution quoted him as saying: “Anything can happen in one game — a blown call by an umpire, a bad day at the office. At least in a two-of-three-game series you have some sort of leeway.” Chipper was a little more omniscient than the MLB’s Twitter feed.

The moral of the story is that something like this was bound to happen. I call it the “Murphy-Frondorf Law,” and I record it as follows:

“The probability of something ridiculous happening during a monumental game, or during a crucial part of a game with otherwise lesser importance, is increased more than tenfold from the probability of the event normally occurring.

Hence, the infield fly rule popping up during an elimination playoff game.”

It is important to distinguish the law from the general mantra in sports that “anything can happen.” This law does not describe miraculous comebacks, horrific meltdowns, breakout stardom or anything related to the skill of the players on the field or court or course. I want to make it very clear for future hypothesis testing that this law only describes the probability of events where the players on the field have no control over the outcome. Plus, it’s a law and not a theory, which means you can’t disprove it anyway — take that, high school chemistry students.

I also want to reject challenges that the Murphy-Frondorf Law only exists because of observation bias — one might say that we only notice and remember the crazy things that happen because they happen during big games. But stuff like the infield fly rule never comes up. Baseball Info Solutions reported that only six infield flies were not caught over the past three seasons, and none of them were near as long as the one called on Friday. There are 2430 games in an MLB season, and assuming 70 at-bats per game (a couple less than four at-bats per player), there have been more than 500,000 MLB at-bats over the past three years. Arriving at our rough probability of a dropped infield fly: 0.000012. Indubitably, the probability was multiplied 10 times over for Friday’s wild card game.

For even more exposition, here are other Murphy-Frondorf Law situations, in no particular order:

1) The NFL replacement refs just had to face the challenge of judging the result of that Hail Mary pass at the end of the fateful Seattle-Green Bay matchup a few weeks ago.

2) Former Cardinals manager Tony La Russa and his bullpen coach just couldn’t figure out how to communicate via bullpen phone during Game 5 of the 2011 World Series, a standard conversation and use of technology that occurs almost every game, which of course led to the game-winning double being hit off the pitcher who wasn’t supposed to be in the game.

3) Dustin Johnson lost the chance to compete in a playoff for the 2010 PGA Championship on the 18th hole of the final round when he grounded his a club in a patch of spectator-trampled dirt that was obscurely defined as a bunker for that tournament only.

And that’s just the last two years. There you have it. Indisputable facts. So when the World Series is decided by a Game 7, ninth inning, two-out, uncaught third strike, don’t say the Murphy-Frondorf Law didn’t tell you so.