There are limitations to how much and where a baseball player may apply pine tar to a baseball bat. According to Rule 1.10(c) of the Major League Baseball Rulebook, it is not allowed more than 18 inches up from the bottom handle. An infamous example of the rule in execution is the Pine Tar Incident on July 24, 1983. Rules 1.10 and 6.06 were later changed to reflect the intent of Major League Baseball, as exemplified by the league president's ruling. Rule 1.10 now only requires that the bat be removed from the game if discovered after being used in a game; it no longer necessitates any change to the results of any play which may have taken place. Rule 6.06 refers only to bats that are "altered or tampered with in such a way to improve the distance factor or cause an unusual reaction on the baseball. This includes, bats that are filled, flat-surfaced, nailed, hollowed, grooved or covered with a substance such as paraffin, wax, etc." It no longer makes any mention of an "illegally batted ball". In 2001, MLB approved the use of Gorilla Gold Grip Enhancer in major and minor league games as an alternative to pine tar.
Within league standards there is ample latitude for individual variation, many batters settling on their own bat profile, or one used by a successful batter. Formerly, bats were hand-turned from a template with precise calibration points; today they are machine-turned to a fixed metal template. Historically significant templates may be kept in a bat manufacturers' vault; for example, Babe Ruth's template, which became popular among major-league players, is R43 in the Louisville Slugger archives.
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.
Players can also create complex holes such as ‘two-part holes’ where the players must hit or reach one object before attempting to shoot at the hole. For example, a ‘two-part hole’ could consist of hitting the scoreboard first, and then once they have hit the scoreboard they must hit the ball back to home plate, that would be one hole with the player with the fewest strokes winning the hole. ‘Two-part holes’ are typically saved for the last hole in order to make things more complex and difficult on the leader.