CardSharp

This strategy “rule” is a key concept in NL holdem preflop play. It was originally published by Bob Ciaffone in Pot Limit & No Limit Poker. The rule is as follows:

Any time you’re considering calling a preflop bet on the basis of a combination of implied odds and position, the size of the bet relative to the effective stack size is the primary factor in whether or not you call. If it is less than 5% of the effective stacks, you have an easy call. If it’s more than 10%, you have an easy fold. Anything in between is a judgment call.

Now, this is a very dense piece of advice. Let’s break it down to understand exactly what Bob’s talking about.

Preflop Bet

It’s important to realize that the 5/10 rule is a statement about preflop implied odds. Once you get to the flop and beyond, it should be more obvious what you’re drawing to and more traditional implied odds calculations can be used. The situation where the 5/10 rule is applied is when you have action in front of you before the flop, and need to decide whether to cold call or not. Note that in NL, unlike limit holdem, cold-calling raises is frequently correct.

Implied Odds

Implied odds situations are ones in which you will win far more money if you win the hand than you will lose if you don’t. Implied odds situations arise in NL when you have a draw to a very big hand, but that draw doesn’t hit that often. You invest a little to see if it pans out, and if it does, then you (hopefully) win far more than you invested from someone with a weaker made hand. There are three basic classes of implied odds opening hands in NL holdem: small-medium pairs, suited aces, and suited connectors & 1-gappers. The pairs are looking to flop a set, and the rest a straight or flush draw (or pat hand). The 5/10 rule doesn’t really apply to weaker hands than that, although if the incoming bet is very small (<2%) you may still want to call.

Position

It’s no big secret that position is key in NL holdem, but it’s particularly key when playing hands that won’t hit the board that frequently. This is of course the case will all hands relying on implied odds. While the goal is to flop a monster hand or good draw, reality is that the majority of the time you’ll end up holding air or a very mediocre hand like a pair of aces with no kicker or a middle pair. While these weak hands have to be abandoned to any serious action, you want to win your fair share of pots when no one else hits anything either. In order to make strong decisions with weak holdings you need to be in position.

Of course, there are two types of position. Absolute position puts you last to act. Relative position puts you last to act after an expected bet. Generally speaking, you want absolute position if the original bettor doesn’t usually continuation bet, and relative position (so you can consider a raise-steal) if he does. Without at least a decent chance of having the appropriate type of position, the 5/10 rule doesn’t apply.

Bet Size & Effective Stack Size

The 5/10 rule and indeed all implied odds thinking in big bet poker is based on this simple observation: the size of bets on future streets is a function of the current pot size, NOT of the initial blind/ante size. The 5/10 rule uses the size of the current bet as a proxy for the size of the pot after betting is completed, but the concept is still the same – you’re making sure there’s enough money behind that you get paid off if you hit. If the ratio between the bet size and stack size is too narrow, there’s not going to be enough money to pay you off. You’re priced out and need to fold.

Note that the stack sizes here are effective stack sizes – the smaller stack of you and the initial bettor. It doesn’t matter if the bet is 2% of your stack if it’s 25% of his – you can’t get paid off. If there are callers inbetween, and one of them has a larger stack than the initial bettor, it might be reasonable to think in terms of his stack size instead of the original bettor’s.

Judgement

It the range between 5% and 10%, you have to use judgment about whether to call. Here are some factors to consider:

• Be more likely to call the closer you are to 5%.
• Be more likely to call if you the bettor stacks off a lot.
• Be less likely to call if the bettor continuation bets frequently.
• Be more likely to call if you expect multi-way action without a raise.
• Be less likely to call if you have aggressive players behind you who might re-raise since you will probably have to fold if that happens.
• Be more likely to call if you’re guaranteed position (as opposed to just likely to have it)
• Be more likely to call if your hand is stronger ie TJs instead of 75s.
• Be less likely to call if there is both a raise and re-raise in front of you because the action will still open when it gets back to the original raiser.
• Be more likely to call against a tight or rockish initial raiser from early position who may well have a big pair or AK since it’s easier to get paid off by those hands.

Now you know the 5/10 rule.