About Bingo, I wrote:

<< There are at most five equivalence classes of lines: center horizontal(1), off-center horizontal(4), center vertical(1), off-center vertical(4), and diagonal(2). Is the distribution for diagonals the same as for the center horizontal?

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And Dan A. responded:

... If the only question is Find the probability P(X;n) that line X is filled after n draws, then there are only 2 relevant categories for X: those that need 5 matching draws, and those that need only 4.

I was a little fuzzy on the question last night. Try this: I want to find P_1(X;n), the probability that line X is filled on draw n _and_ that no line was filled after n-1 draws. The other question I'm asking is P_k(X;n), the probablity that line X is filled on one of k boards on draw n, and that no line was filled on any of the boards before that. Now what are the equivalence classes for X? Dan Hoey Hoey@AIC.NRL.Navy.Mil