This study examines the difficult choice faced by members of a striking bargaining unit between withholding labor or crossing the picket line in violation of the prevailing behavioral norm. Using duration analysis, we test a model of crossing behavior using data on individual football players during the 1987 National Football League strike. A notable finding is that nonwhite players are less willing to cross the picket line if their team union representative is also nonwhite. Willingness to cross the line is also influenced by teammate crossing and proxies for expected career length, demand for current income, and expected benefits from union demands.