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New York Yankees third baseman Josh Donaldson learned a hard lesson during Tuesday night's American League Division Series opener vs. the Cleveland Guardians: A home run is not a home run until it clears the wall. 

That may sound self-evident, but take a look at this:

In the fifth inning and with the score tied, Donaldson sliced a pitch from Guardians right-hander Cal Quantrill to right field. He then took on the leisurely pace of a batsman who believes the ball he struck is heading for the seats. Donaldson even high-fived first-base coach Travis Chapman as he made his way past the bag.

There was just one problem. Donaldson's ball did not sail into the bleachers. Instead he had hit the closest thing that can be described as Schrödinger's home run: a ball that bounced off the top of the wall and deflected almost directly to Guardians outfielder Oscar Gonzalez. Gonzalez turned and delivered a strike to shortstop Amed Rosario. Rosario then threw behind Donaldson to first base, where Josh Naylor applied a tag and Donaldson was ruled out. Replay even confirmed as much.

Donaldson's non-home-run was odd for a number of reasons, including the unlikelihood of the ball hitting the wall in the exact spot and with the exact spin that would cause it to ricochet back to Gonzalez instead of into the stands. There was also the matter of no fans making contact with the ball. A gentleman can be seen attempting to catch it, but coming up empty handed -- just like Donaldson.

The Yankees took the lead later in the inning and went on to win 4-1, but credit the heads-up play and the strong, accurate throws by Gonzalez and Rosario, and debit Donaldson for taking his home run for granted.