Bankroll management is singly handedly the most important skill that a poker player can have. Without it, even the best players in the world would go broke. After all, let's face it, if you don't have money you can't play poker. It's as simple as that.
What Exactly is Bankroll Management?
Bankroll management is simply the act of playing games that are within the means of your bankroll. This can be both in terms of money and/or game variation.
Bankroll management is important because all poker players will go through a bad run of cards, otherwise known as variance. Variance (good or bad) is completely normal and unavoidable, regardless of your abilities. So you will want to practice good bankroll management and have solid guidelines in place so that your bankroll can withstand the negative variance without busting.
Bankroll Management Guidelines
The bankroll guidelines that are best suited for you will depend on what kind of game you are playing. It will also vary slightly depending on the betting variation of that game. I'll cover what is considered the standard guidelines for each game/variation below.
Tournaments
Larger MTTs have tons of variance. You play so many games and either cash small or don't cash at all. Then every once in a while you go deep or take a tournament down and score big. Rinse, and then repeat.
Because of how intermittent cashing for larger sums of money is in big tournaments, you will want to make sure you have at least 100 buy-ins for the stakes you want to play. This means that if you want to play in $10 tournaments, your bankroll should be at least $1,000.
Now, keep in mind that this figure will vary slightly depending on a few variables:
Size of the field: A field of 500 is much easier to play through then a field of 5,000. The bigger the field, the longer you'll go between cashes. You will want to be sure to adjust your bankroll guidelines accordingly.
Re-buys and/or Add-ons: If you regularly play in tournaments that have the option to re-buy or add-on you'll need to set a limit of each you're willing to pay for in each game you play. For me personally, I will generally buy in and then pay for one re-buy and one add-on. This leads to me paying 3x the original buy-in for that tournament. You'll want to adjust your guidelines for this as well. I would suggest having at least 200-300 buy-ins for the stakes you wish to play minimum.
Stakes: The higher the stakes you play, the better the competition. In other words, it'll be much harder to cash in a $500 tournament than it would be to cash in a $10 tournament. So the higher you play, the bigger the bankroll you'll want to have.
Sit n Go's
Sit n go's aren't going to have near the variance that you'll experience in large MTTs. So you won't need as big of a roll to play them. For most sit n go's, you should be able to get by with 40 buy-ins. This means if you want to play a sit n go with a buy in of $10, you'll want to have a bankroll of at least $400.
With that said however, you'll still want to adjust the size of your bankroll depending on the size of the sit n go you're playing, the stakes and whether it's a turbo or non turbo. For example, I might lean towards having 75+ buy-ins if I were to solely play 180 man sit n go's whereas I might be perfectly content with having 50 buy-ins for playing 18-man sit n go's. If they were turbos, I'd increase the size of my bankroll. The same will hold true the higher up I move in stakes.
Cash Games
The rule of thumb for cash games is to have a minimum of 25 full buy-ins for the stakes you wish to play. So for example, if you wanted to play 100nl, you'd need a bankroll of $2,500 assuming that you buy in full for $100.
Now, although 25 buy-ins is the standard recommended bankroll, I would suggest that you have more if possible. Successful poker player Dusty "Leatherass" Schmidt actually recommends that you have 100 buy-ins for the games you want to play. Although he admits that this is very conservative, his reasoning is that he would like the opportunity to play at whatever stakes he wants, especially if a plus EV opportunity arises (like playing with a fish). He also mentions that he likes to be well rolled so he doesn't worry about busting, therefore always playing his "A" game.
Bankroll Guideline Variables
In addition to the guidelines outlined above, there are other variables that you should consider when determining how big a bankroll you need to have.
Are you playing full ring or short handed? Short-handed poker (like 6-max) is going to require a bigger bankroll in comparison to full ring because you play more hands and are in marginal situations frequently. In short, the variance is much more extreme in short handed poker in comparison to full ring.
Are you playing no limit, pot limit or limit poker? Since you can risk more of your stack (bankroll) in games with little to no betting cap, betting variations like pot and no limit will have more variance in comparison to games that limit betting.
What is your playing style like? The more aggressive you are the more hands you play and more marginal situations you'll find yourself in. This will lead to more frequent and much larger swings. So if you are aggressive, you'll want a larger bankroll. The tighter you are, the smaller your bankroll can be since you'll experience all of this (marginal situations and swings) to a lesser extent.
Do you play for fun or for a living? If you play poker solely for fun, you can get by without having a large bankroll since your money is for playing only. However, if your poker winnings pay your bills, you'll want to have a larger bankroll to offset your regular withdrawals. Not only that, but you'll want to have extra funds or even a savings in case you go on a downswing and don't make money for a few days, weeks or even months.
Moving Up/Down in Stakes
When looking to move up or down in stakes many players will use what is referred to as the floor/ceiling method. These are predetermined amounts that a player must have in order to move up or that will force them to move down. So for example, say you have a floor/ceiling of 12 buy-ins and 25 buy-ins. This would mean that if you hit 12 buy-ins or below for your current game, you hit the "floor" and must move down. However, if you hit the "ceiling" of 25 buy-ins for the next stake up, you can then move up if you feel you're ready.
Now, most players won't have a problem with moving up. In fact, many will move up too soon without having the proper bankroll to support them and often they'll bust. Or, many players will move up or start at a certain limit and hit the "floor" but not have the discipline to move back down. It's very important to realize that going broke is much worse than having a damaged ego from having to move back down. Everyone has to do it at some point in their career. If you hit your "floor," be sure to move down. If you were good enough to move up in stakes in the first place, you'll be back before you know it.
Bankroll Management Summary
Hopefully by now you see how important bankroll management is. Without a bankroll, you simply cannot play poker. So it's imperative that you manage it well. This means sticking to the guidelines I outlined above as well as moving up/down in stakes when warranted.