High Quality Content by WIKIPEDIA articles! A baseball bat is a smooth wooden or metal club used in the game of baseball to hit the ball after the ball is thrown by the pitcher. It is no more than 2.75 inches in diameter at the thickest part and no more than 42 inches (1,100 mm) long. It typically weighs no more than 33 ounces (0.94 kg), but it can be different from player to player. The batter swings the bat with two hands to try and hit a pitched ball fair so that he may become a runner, advance bases, and ultimately score a run or help preceding runners to score.