The chance of Luis Castillo breaking DiMaggio's record is 1 in 111 based on this season, one in 1430 based on his career. Let me note that the probability of Castillo having 92 hits in 297 plate appearances this year is about .01 (based on his career numbers), which some would call statistically significant (1 in 100 chance of happening). It still could be good luck, but it could also be that his hitting ability has changed.