What happens if you REALLY knock the cover off the ball?

It’s one of the most famous moments in baseball movie history. Roy Hobbs, the middle-aged rookie, is pinch-hitting for New York Knights star rightfielder “Bump” Bailey after Bailey was benched for lack of hustle. It’s Hobbs’ first big league at-bat, and as he strides towards home plate, signature “Wonderboy” bat in hand, manager “Pop” exhorts him to “Knock the cover off the ball!”

Hobbs, of course, obliges. Literally.

In The Natural, Hobbs’ freakish accomplishment leads to Bailey being threatened with a benching, Bailey running into a wall in an attempt to keep his job and later dying as a result, and Hobbs stealing Bailey’s girlfriend, Memo, before cheating on Memo with Iris. (Don’t believe me? Go rewatch the movie. That’s what happens.) In any event, far more interesting than the movie is the question of what would happen if a hitter actually hit the cover off of a baseball during a game.

Believe it or not, this feat actually is far more common than you might think - and a lot less impressive. Most recently, Phillies outfielder Bryce Harper did it, but there wasn’t any lightning and no, he didn’t even reach base.

Four years ago, New York Met and former domestic abuser Jose Reyes hit the cover off of a ball that traveled about four feet.

Two years before that, Martin Maldonado did it, and actually reached base as a result, though he, too, didn’t hit it into the outfield.

Ryan Ludwick did it too.

And Javier Baez.

It doesn’t just happen in the big leagues, either. Take a look at Division II catcher Zach Tyson injure a baseball here.

Of course, there’s more than one way to take a cover off a ball.

You can probably figure out from the clips here - and from the movie The Natural - what the rule says about what happens. And yes, there actually is a rule on this - or, more precisely, a comment to a rule.

Rule 3.01 Comment: Should a ball come partially apart in a game, it is in play until the play is completed.

This presents some interesting questions, however. What happens if a ball comes completely apart, The Natural style? The rule doesn’t really specify, nor do we know what the difference is between “partially apart” or “completely apart.” In theory, every ball coming apart at all is “partially” apart unless it ceases to be a baseball at all.

So, what is a baseball?

The ball shall be a sphere formed by yarn wound around a small core of cork, rubber or similar material, covered with two strips of white horsehide or cowhide, tightly stitched together. It shall weigh not less than five nor more than 5¼ ounces avoirdupois and measure not less than nine nor more than 9¼ inches in circumference.

The closest we’ve come in recent years to testing this rule is Maldonado’s at-bat above, where the ruling on the field was correct - fielders attempt to finish the play with the ball in whatever condition they find it.

So in the movie, the outfielders did the right thing trying to throw a gigantic wad of string towards the infield. The way the rule is written, it’s the sphere of yarn that forms the ball, not the cover. That’s why Hobbs ends up at third base with a triple even though the cover of the ball doesn’t make it farther than the pitcher’s mound; as the rule suggests, the cover isn’t the ball.

In other words, as a matter of the rules of baseball, The Natural got this particular tidbit right. As for relationship advice, don’t follow The Natural. That’s what Bull Durham is for.