Baseball bats are made of either wood, or a metal alloy (typically aluminum). Most wooden bats are made from ash. Other woods include maple, hickory, and bamboo. Hickory has fallen into disfavor over its greater weight, which slows down bat speed, while maple bats gained popularity following the introduction of the first major league sanctioned model in 1997. The first player to use one was Joe Carter of the Toronto Blue Jays. Barry Bonds used maple bats the seasons he broke baseball's single-season home run record in 2001, and the career home run record in 2007. In 2010, the increased tendency of maple bats to shatter has caused Major League Baseball to examine their use, banning some models in minor league play.
It is not clear why pregame infield fell out of favor in the majors. Today, coaches hit balls to infielders and outfielders during batting practice. Most players go at it leisurely, lobbing balls back in or across the diamond. That rankles old-school players like Jerry Kindall, a former major league infielder who coached Arizona to three N.C.A.A. titles before retiring in 1996.
Maple bats in particular were once known (circa 2008) to potentially shatter in a way that resulted in many sharp edges, sometimes creating more dangerous projectiles when a bat broke. Maple bat manufacture evolved significantly, in cooperation with Major League Baseball, paying special attention to grain slope, and including an ink spot test to confirm safest wood grain orientation.
Many players "bone" their bats, meaning that before games, they rub their bats repeatedly with a hard object, believing this closes the pores on the wood and hardens the bat. Animal bones are a popular boning material, but rolling pins, soda bottles and the edge of a porcelain sink have also been used. Pete Rose had his own way of hardening his bats: he soaked them in a tub of motor oil in his basement then hung them up to dry.
“They’re not moving, their feet are apart, their gloves are on the ground, backs are flat, and they’re working down to up, out to in, basically a steady roll back and forth probably 15 to 20 each,” Bates said. “Then they’ll turn their body, work glove side for another 15 to 20, and backhand 15 to 20. No movement, really, just making sure we’re watching the ball roll into our glove, fielding it, and doing all the things fundamentally correct.”
Even in those formative years, authorities on the game warned the practice of hitting fungoes should be limited to coaches. Henry Chadwick, one of baseball’s earliest proponents, claimed “The weakest batting is shown when the batsmen indulges in fungo hitting,” according to the Art of Batting. Others agreed that the practice was bad for training a batter’s reflexes: “While watching some of our freshmen practicing ‘fungo’ batting the other afternoon it occurred to me that it was about the worst kind of practice a batsman could imagine in training his eye in batting,” a writer claimed in the March 3, 1886 edition of The Sporting Life. “It trains the eye to meet the ball in batting it in a manner which never occurs in actual play. It ought to be prohibited on every well regulated ball field.”