bankroll: 100 times your large bet?

I was wondering why you are supposed to take 100 times your large bet. I know it is a general rule of thumb to have that amount and I was wondering if there are formula's or statistical evidence that supports having 100 times your big bet. Also what exactly does having that amount insure you? What risks are you taking if say you only have 50 times your large bet? Thanks a lot.

using BJRM....for a 62/104 double deck game using Halves Count...100 max bets is 3.79% risk of ruin, 50 max bets is almost 20% risk of ruin. Full Kelly is 13.51% risk of ruin, half kelly is about 1.8% risk of ruin. (without proper resizing).

So, if you're willing to resize everytime you lose 1/3 of your bank 100 max bets is fairly safe, whereas, 50 max bets, at least for fulltime players, is suicidal.

The short answer is that a bank of �100 times Max Bet� will give you a static Risk of Ruin of less than 1%, depending on the exactly what �max bet� is. If you place you play a shoe game with good rules (S17-DAS-LS) and you play your Max Bet at a HiLo true count of 4, then you are looking at an RoR of about 0.8%.

I referred to this above as a static RoR, and this is an important qualification. By this I mean, your RoR under two assumptions: you never resize your bets, and all winnings are re-invested into the bank with no leakage.

If you are taking winnings out of the bank, your RoR goes up dramatically. If you resize your bets periodically, your ROR goes down considerably.

So the next issue is: what are the consequences of bankroll ruin. If you are a full-time pro, then you bank is a very large part of your net worth. And you need to some of f your winnings to live off. So a conservative rule is called for.

However, most of the readers of this board are not full-time players. Part-time players, with other jobs, can afford to play to a higher RoR. For many of them, this rule is excessively conservative.

.. a specific and concise (albeit approximate, as it had to be) answer.