Looks like I need to read up on max bet - I'd assumed max bet varied based on the bet so as to be whatever the maximum was that would incur loss to the house of 1% of capital.  From what you're saying it's a fixed amount regardless of which bet is chosen (so X BTC whether they go for a 1 in a million shot or a a 98% shot).  I'd assumed the main exposure would be on people gambling the max they could on the most extreme odds bets.