Quote:
Originally Posted by tain
How does this sit in with good bankroll management, whereby if I have 20BB playing 50nl, and I'm playing 10 tables at once, and I bust out on all of them, my next game should be in 25nl until my bankroll returns to 20BB? Does risk of ruin not take this into account? Or does it all depend on how many tables you play at once, etc?
risk of ruin does not account for moving up or down. it's a very simple formula actually, based on this concept:
imagine somebody offers you a bet, say a coinflip, with favorable odds. Say he'll pay you $1.10 for every $1 you wager, when you win the flip. You can choose any amount to bet, and you can take the bet over and over again. You have a fixed starting bankroll.
naturally, you don't want to bet your whole roll on the first toss, because you have a 50% chance of busting out. Not only do you lose all your money, you now can't take this very profitable bet. Nor do you want to bet too tiny fraction of our roll. We do like winning money as fast as reasonable.
So we do some math and figure out the proper balance between the expectation of the bet, the variance of the bet, and how sure we want to be that we don't go broke. You can't ever be 100% sure, because no law of physics prevents the coin from flipping against you every time from now to eternity. But that's unlikely.
Anyway, you're probably not interested in the actual arithmetic. google risk of ruin and you'll get more math than you could want. But that's the model: a bet iterated, 1 expectation, 1 variance, 1 risk of ruin. nothing more complicated. how you use that formula in bankroll management is up to you.
being willing to move down when you're losing effectively prevents you from going totally busto, assuming you don't lose everything at .01/.02. It allows you to play with a smaller bankroll than you'd need otherwise. In fact, the 20 buyin guideline is too aggressive without this effect.