During the NCAA basketball tournaments from 2002 to 2005, men's games produced 27% more upsets than women's games. To test whether these unpredictable results were due to gender differences, we conduct logit analysis to explain upsets by gender and other potentially significant variables, including differences in competing teams’: (i) RPI scores, (ii) percentage of freshmen, (iii) percentage of seniors, (iv) top scorer's total points and, (v) top three scorers’ total points. These analyses suggest that gender plays a significant role in explaining predictability.