Two definitions of crippling rate, cripples! shot and cripples! hit, have been employed in field studies to compare waterfowl wounding losses for lead and steel shot. Properties of these 2 definitions were compared using the Louisiana Lacassine Study data (Hebert et al. 1982) and a mathematical model. Cripples! shot was shown to decrease to a limit of 0 with an increase in misses even though the actual number of cripples remains constant. Cripples! shot, and not cripples! hit, was subject to an interaction between load and distance. The susceptibility of cripples! shot to an interaction between load and distance may result in the conclusion of no significant difference in crippling rates for the loads, regardless of what the actual relative wounding losses might be. Cripples!hit was more reliable than cripples! shot for comparing wounding losses for lead and steel shot.