Inside pitching is a common and legal tactic in baseball, and many players make use of brushback pitches, or pitches aimed underneath the chin, commonly referred to as 'chin music', to keep players away from the plate. However, throwing at a batter intentionally is illegal, and can be very dangerous. When an umpire believes a pitcher has thrown at a batter intentionally, a warning is issued to the pitcher and the managers of both teams. From that point on, any pitch thrown at a batter can cause the pitcher and the manager (if believed to have ordered the beanball) of the offending team to be ejected immediately from the game. Serious offenses such as a ball thrown at the head (called a beanball) can result in the immediate ejection of the pitcher, and the manager if he ordered the beanball, even without a warning.
Often, if a player is acting rude or unsportsmanlike, or having an extraordinarily good day, the pitcher may intentionally hit the batter, disguising it as a pitch that accidentally slipped his control. Managers may also order a pitcher to throw such a pitch (sometimes called a "plunking"). These pitches are often aimed at the lower back and slower than normal, designed to send a message more than anything else. The opposing team usually hits a batter in retaliation for this act. The plunkings generally end there because of umpire warnings, but in some cases things can get out of hand, and sometimes they lead to the batter charging the mound, bench-clearing brawls, and several ejections. Such plunking duels are more common in the American League than in the National League, because in the NL the pitchers must bat for themselves and open themselves up to direct retaliation (although hitting a fellow pitcher is a serious breach of baseball etiquette). The most common sign the catcher gives, if he or the coach wants to plunk a batter is simply giving the pitcher the middle finger.
There was a game in 1966 where New York Mets pitcher Dick Selma hit the Phillies' Richie Allen (as Dick Allen was still being called in the news media of the time); then Phillies pitcher Bob Buhl hit Selma, causing Selma to be removed for a pinch-runner, and then new Mets pitcher Jack Fisher hit Buhl.
