Clarifications
A pitcher is allowed to feint toward third (or second) base, and then turn and throw or feint to first base if his pivot foot disengages the rubber after his initial feint. This is called the "fake to third, throw to first" play. However, Major League baseball is considering classifying this as a balk beginning with the 2013 season.
If no runners are on base and the pitcher commits an otherwise balkable action, there generally is no penalty. However, delivering a quick return or pitching while off the rubber (which constitute balks when runners are on base) results in a ball being called with the bases empty. If the pitcher should commit an act confusing to the batter with nobody on, or if he stops his delivery or otherwise violates because the batter steps out or otherwise acts confusingly, time is called and the play restarted without penalty (whether or not runners are on base). If a pitcher repeatedly commits illegal actions without runners on base, he may be subject to ejection for persistently violating the rules.
If, during an attempt to execute the "hidden ball trick" (where the defensive team deceives the runner(s) as to the ball's location while the play is live), the pitcher stands on the rubber prior to the fielder revealing the ball and applying the tag, the runner is not called out. Instead, it is a balk, with all runners on base being awarded their next base.
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