Bank roll requirements in Omaha 8/b

You need a much smaller bankroll to play split-pot games than to play regular high games. As a result, you need a much smaller bankroll to play O8 than you do to play a holdem game of a similar level.

Here's what Mason Malmuth says in his Poker Essays (btw, very good book - well worth purchasing):

Conclusions

1. To play an equivalent game of O8, you need a bankroll that's only 20-40% of the size bankroll needed to play holdem.
2. A very good winning player can play O8 with a ridiculously small bankroll.
3. Note that these numbers assume you will stay at this level. If you are willing to move down, you need a much smaller bankroll. For example, take a Good Player from above playing $3-6. He needs a bankroll of $300 for the $3-6 game. So what does he need to begin playing $5-10? Just $301. Because as soon as he loses $1 he can move back down to $3-6 (that's a bit of an exaggeration - he needs more than $301, but hopefully you see the point).

What I recommend

If you are a winning player, I recommend aggressively moving up in levels. The data I've reviewed show some increase in difficulty as you move up levels, but not a ton. As a result, I think its primary the bankroll that determines how what $ level your opponents will play at. What I do is sit at the highest level tables I can where I have 25xBB. For example, 25xBB at a $2-4 tables is $100. So to sit at 2 $2-4 tables requires $200. Sitting at $3-6 tables would require $300. So I arbitrarily pick the middle of those amounts as a safety net, say $250. So as soon as my bankroll hits $250 I will start playing at $3-6 tables. If it drops below that, I'll drop down to the $2-4 tables. Of course, I know I'm a winning player at $3-6.

Important Note: I define your bankroll as the money you really don't want to lose, but can if you have to. So you can redeposit with other funds if you really need to but would strongly prefer not to. If you truly have no other money whatsoever for poker, you should be signficantly more conservative that these recommendations.

If you don't know you are a winning player, then I'd recommend proving that through 10k hands first.

So, to summarize:

1. Aggressively Move up Levels. Players are bad up through $5-10 at Party. If you are a decent winning player at even $1-2, then you can probably beat the $5-10 game. I know this from experience.
2. Aggressively Move Down Levels. If you run into trouble, start running bad, go on tilt or just lose confidence, then move back down in levels. Poker is about winning money, not about pumping up your ego. I jumped up too high and played $20-40 and it put a giant dent in my bankroll to the point where I had to drop to $.5-1 or reload. I decided to play fundamental O8 and dropped to .5-1. I ended up quickly rebuilding by jumping up until I had the bankroll again. It took about a month til I was back in the $10-20 game. If it's a choice between pride and cash, take the cash.
3. Maintain ~120 BB's in your poker bankroll. The general recommendation for limit holdem is 300BB. Given the above chart, you need somewhere around 40% of that for O8. So I'll make a blanket recommendation of 120BB for O8. That means if you're playing $10-20, you should have at least $2,400 to avoid risk of ruin. I would also adjust the 120BB number based on other factors. If you truly have no other way of replenishing your funds, then I'd want more BB than that. If you are an aggressive player, I'd bump that number up. And if you are playing in an aggressive game with lots of preflop raising, then I'd bump that number up.