734 feet (5/22/63, Yankee Stadium Façade* – Pitcher: Bill Fischer, Kansas City Athletics – Left-handed)

Mickey said that the "hardest ball I ever hit" came in the 11th inning on May 22, 1963 at Yankee Stadium. Leading off in the bottom of the 11th, with the score tied 7-7, A's pitcher Bill Fischer tried to blow a fastball past Mickey.

Bad idea. Mickey stepped into it and, with perfect timing, met the ball with the sweet spot of his bat, walloping it with everything he had. The sound of the bat colliding with the ball was likened to a cannon shot. The players on both benches jumped to their feet. Yogi Berra shouted, "That's it!" The ball rose in a majestic laser-like drive, rocketing into the night toward the farthest confines of Yankee Stadium. The question was never whether it was a home run or not. The question was whether this was going to be the first ball to be hit out of Yankee Stadium.

That it had the height and distance was obvious. But would it clear the façade, the decoration on the front side of the roof above the third deck in rightfield? "I usually didn't care how far the ball went so long as it was a home run. But this time I thought, 'This ball could go out of Yankee Stadium!'"

Just as the ball was about to leave the park, it struck the façade mere inches from the top with such ferocity that it bounced all the way back to the infield. That it won the game was an afterthought. Mickey just missed making history. It was the closest a ball has ever come to going out of Yankee Stadium in a regular season game.**

The question then became "How far would the ball have gone had the façade not prevented it from leaving the park?" Using geometry, it is possible to calculate the distance with some accuracy. The principle variable is how high the ball would have gone. If we assume the ball was at its apex at the point where it struck the façade, using the Pythagorean Theorem ("In a right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides") the distance would have been 636 feet. (For a more complete explanation of the calculations and complete description of this and other Mantle homers, see Explosion! by Mark Gallagher. This book is the definitive book on Mantle's homers. Unfortunately, it is out of print. It may be available at your local library.)

So how do we get 734 feet? In the example above, we assumed that the ball was at its apex when it struck the façade. However, observers were unanimous in their opinion that the ball was still rising when it hit the façade. How do we determine how high the ball would have gone? In fact, we cannot. From this point forward all numbers become guesses, estimates of how high we think the ball might have gone. A conservative estimate would be 20 feet. Those 20 feet make a major difference. They cause our calculation to go up almost 100 feet, to the 734 foot number listed above. Is 20 feet a fair estimate? Those present when the ball was hit feel that it would have gone at least that much higher, and many feel that the 20 foot number is far too low. It is all just a guess.

This is a good example of what can happen with estimates, especially computer estimates that determine the length of home runs now. Most of the home run distance numbers used today are the result of computer estimates of how far the ball would have traveled without obstruction. (One of these programs gave the 734 foot number listed.) Whether or not this is a fair number is a matter of opinion. However, if the distance of this home run is disputed, then the distance of many of the home runs hit by today's players must be questioned. While the software used for home run distances has greatly improved, there remain questions as to its accuracy. It is important to note that many of Mickey's home runs were measured to the point they actually landed, leaving no question about the accuracy of the distance reported.

* The façade was the decorative facing along the roof of the old Yankee Stadium. Mickey hit the façade in regular-season games at least three times during his career: May 5, 1956 off Moe Burtschy, May 20, 1956 off Pedro Ramos, and May 22, 1963 off Bill Fischer.

** Legend has it that Mickey hit balls completely out of Yankee Stadium up to three times during batting practices. Supposedly Mickey did it twice left-handed and once right-handed. Witnesses of these incredible feats include fans, stadium vendors, teammates and opposing players.