School was out for the day and we were ready to play ball. Only one problem--we had bats and gloves, but no one had remembered to bring a baseball. All we could turn up was a tennis ball. We decided to play anyway.

I took the long jog out to right field as Eddie positioned himself next to home plate, which was a cardboard dinner plate. The first pitch came in high. Andrew, the pitcher, had to get used to the light ball. The next pitch came right down the middle. Eddie swung and the ball vanished into the sky. It was headed in my direction. I ran to make the catch but misjudged the ball's trajectory--the tennis ball lost speed faster than a baseball. I positioned myself to play the ball on the bounce. Boy, did it bounce! High over my head and into the woods.

I had just learned that balls are specifically designed for a particular sport. Using a ball designed for tennis in a baseball game produced strange results.

To understand what happened to me back in my grade school days I suggest that you take a tennis ball and a baseball, hold them side by side at waist level, and drop them onto a hard, bare floor. The baseball will bounce back only about a third as high as its starting height, well below knee level. But the tennis ball will bounce higher, rising to half its initial height.

Balls are suited to the games that we play with them. A change in the bounciness of a ball can drastically affect a game--as the history of baseball demonstrates. When baseball was invented, there were no polymer chemists around to brew up a rubber with the appropriate bounciness. As the game and the ball evolved, the game's character and dimensions changed. Prior to 1911, the baseball was a lifeless version of its modern counterpart. During this "deadball" era, long base hits were rare, and "hitting it where they ain't" was the strategy of the day. In 1911, the use of a corkcentered, springier, "lively ball" made the home run king, and paved the way for Babe Ruth, Hank Aaron, and generations of fence-busters.