When you grab a baseball, the first thing you might think is how hard it is. You don't necessarily think of a baseball as bouncy. But that's exactly what a ball does when it hits a bat. The bouncier the ball, the further it will travel when hit. Another word for bouncy is elastic, which means that when an object is deformed by an collision, it tends to bounce back, returning the kinetic energy of the impact into motion in the other direction. Objects that are not bouncy, or elastic, tend to dissipate the energy of the collision as heat, rather than returning it as motion. The measure of this bounce is called the "coefficient of restitution."

Join us as we explore the anatomy of an official National League baseball!

No ball is perfectly elastic; the elasticity of a particular ball depends on its construction. If you change the bounciness of a ball, you radically change the game. The modern baseball is tightly regulated: It has a rubber-covered cork core, which is then wound tightly with yarn and covered with alum leather. It must be between 9 and 9 1/4 inches in circumference, and 5 to 5 1/4 ounces in weight, and have a coefficient of restitution of no more than 0.578, no less than 0.514.

But in the early years of the game, prior to 1848, baseballs were very bouncy, built with a solid rubber core, and were only about 3 inches in diameter. Hitting these "lively" balls, some pro teams tallied as many as one hundred runs per game. As the game evolved, bigger, heavier, less bouncy balls were developed. Referred to as "dead balls," these balls didn't travel as far or as fast as the lively balls. Before the characteristics of the ball were regulated, home teams could choose which kind of ball they would use: If you had better batters than the other team, you'd choose a lively ball; if your team's strengths were pitching and fielding, you'd choose a dead ball.

In 1910, Albert G. Spalding, a former pro who started the company that became the primary supplier of baseballs throughout the world, began making balls with very lively cork centers. The balance of power in baseballs shifted to the hitters, and pitchers resorted to guile to fool the batters: Spitball, sinker, and knuckeball techniques were all perfected around this time -- as was scuffing balls with dirt or emery boards. Many baseball historians assert that after 1920 the major leagues introduced an even livelier baseball to encourage power hitting and draw fans back to the games after the Black Sox gambling scandal. A drastic change in the game resulted: In 1919, National League hitters hit 139 home runs; in 1921 they hit 460. By 1930, teams scored 3.5 more runs per game than in 1915, and home runs totaled 1,565 across the league, up from 384 in 1915. Others dispute the "juiced" ball theory, saying that during the same time period baseball authorities outlawed tampering with the ball, depriving pitchers of some of their most effective weapons, and letting the hitters have a field day.

Since then, there have been accusations that Spalding periodically introduces lively or "juiced" balls, made by winding the yarn inside the ball tighter. Players have complained of balls being too dead only once, during the WW II years, when a rubber shortage forced Spalding to make balls with a less bouncy balata rubber core.

Clearly, applying new technology to the equipment of any game can result in fundamental changes in the game itself. What if the rule-making organizations were to allow technological advance without restriction? What would the game be like then? Even just using the existing technology like titanium bats and more elastic balls, we could play a game of baseball in which scores like 50-37 would be common. But what if fielders were allowed to wear jet packs with which to chase down the new high-velocity drives hit by batters? The debate between the strong traditions of baseball and the search for a technological "edge" will no doubt go on, and time will reveal what kind of baseball future generations will play.

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