Online players sometimes take certain details for granted. Without any prior knowledge of calculation, we can instantly know the following -

- The minimum possible raise sizing.
- The amount of chips needed for a pot-sized raise.
- Whether the action is still open for a re-raise.

Of course, we can always ask the dealer these questions if playing live. Some might find this awkward, however, and it also might not be beneficial for our image. Let’s review the basic rules for raising in poker so that we will always have the freedom of knowing exactly which options are available to us.

Even for those of us who play poker online, a solid grasp of the rules can help us to plan our hands more effectively and understand the flow of action better.

MINIMUM POSSIBLE RAISE

Consider the following -

BTN open-raises to 3bb. SB folds. BB 3bets to 10bb.

What is BTNs minimum possible 4bet sizing?

It might surprise us to learn the relatively few players can answer this question easily. There are two reasons for this -

1. Online players don’t even need to think about it (calculated automatically).
2. Live players probably won’t be using the minimum sizing anyway.

So take a moment and think, what is the minimum possible 4bet sizing here?

The rule governing min-raising is mostly straight-forward, although sometimes preflop scenarios are a little more complicated. The minimum raise sizing available is identical to the size of the previous raise. This rule is slightly easier to conceptualise using a postflop scenario. If player A bets \$5, then the minimum raise size that player B can use is an additional \$5 for a \$10 total bet.

The same logic can be applied to our preflop scenario, but it’s important to keep in mind that BB’s raise size is not 10bb. The previous bet before this was the 3bb BTN open. BB is, therefore, raising by 7bb, not 10bb. BTN’s minimum 4bet sizing is hence 17bb, an additional 7bb. Some players might assume that BTN has to raise to at least 20bb because this is double BB’s 3bet sizing, but it’s BB’s raise sizing we are interested in, not his total bet.

Using the same logic, we should be able to deduce that BB’s minimum 3bet sizing is 5bb. Although BTN is raising to 3bb, he is only raising the bet by an additional 2bb over the mandatory BB post. By extension, BTN’s minimum open-raise sizing preflop is 2bb (i.e. double the BB’s 1bb investment). It’s impossible to open-raise preflop to 1.5bb total, the open-sizing needs to be at least 1bb larger than BB’s post.

CALCULATING A POT-SIZED RAISE

Calculating a pot-sized raise is notoriously something that players struggle with. It might seem as easy as looking what’s in the middle and raising by the same amount, but it’s ever so slightly more involved than this.

Calculating a pot-sized raise is especially important for playing poker variants with pot-limit betting structures. Pot-Limit-Omaha is currently the most widely available poker variant which uses a pot-limit betting structure. Now, of course, we should feel free to ask the dealer at any point, but it’s so much easier if we can calculate a pot-sized raise for ourselves.

See if you can answer the following question:

Flop Situation. \$10 in the middle.

Villain bets \$8

We decide to make a pot-sized raise. What should our sizing be?

Take a moment and think. Despite being a fundamental of poker, it’s possible that the majority of poker players cannot answer this question correctly.

There is currently \$18 in the middle, so it’s tempting to think that we can simply raise by an additional \$18 for a total raise size of \$26. This calculation is how many players would answer. Unfortunately, this is incorrect. We can confirm this by looking at the pot-odds our opponent is offered against such a raise. He’d need to call \$18 into a total pot of \$62, which can be expressed as pot-odds of roughly 29%. Pot sized raises can be recognised because they give our opponent precisely 2:1 or 33% pot-odds on the call.

So what’s the trick here? First, imagine we call the bet and see what the total pot-size would be. If we call, the total pot-size would be \$26. This amount is the size of our raiseWe raise by \$26 for a total raise-size of \$34. Our opponent would hence need to invest \$26 into a total pot of \$78 to make the call. In other words, he would be getting exactly 33% pot-odds, which confirms that this is an accurate pot-sized raise.

WHEN RE-RAISING IS ILLEGAL

Re-raising is not always a legal option in poker, even if we have chips behind. This situation occurs when a short-stack has made a sizing smaller than a min-raise because he is all-in

Imagine a three-way flop with the following players:

Pot Size: \$20

Player A (hero): \$100
Player B (shorty) \$23
Player C (villain) \$100

Let’s imagine we have a good hand and decide to make a bet of \$15 on the flop. Player B likes his hand also and decides to shove all-in for \$23. Ordinarily, such a raise size would not be allowed: it is less than the minimum legal raise (an extra \$15 for \$30 total). However, given that player B is raising all-in, the option becomes legal.

Note that he can’t raise to \$20; he must either call, fold, or shove all-in. Player C has the option to raise, his minimum raise-sizing being at least \$15 additional chips. (Note that it doesn’t suddenly drop to \$8 because player B shoved all-in for less than the minimum).

Let’s imagine player C opts to call, and the action is now back on us. We really like our hand, and want to raise, hoping to extract additional chips from player C. Can we do this? No, we can’t. The option of re-raising is only open to us if we have faced at least ONE full-sized raise before the action gets back round to us. If player C had opted to raise the minimum, we could now re-raise. But since player C just calls, there has been no full-sized raise behind us, and our options are limited to either calling or folding.

Of course, all of this is calculated automatically for online players, although amateurs may sometimes be surprised to find that their raise-box is greyed out despite having additional chips left to wager. In live games and home games, the ruling has the potential to cause a significant amount of confusion and debate.

It’s important in the above example that player C is aware of the rules because it might be detrimental to him if player A can re-raise illegally.

USEFUL FORMULAS

Here is a quick summary of the useful formulas we have considered in this article:

Useful Formulas:

Calculating minimum raise = Must be equal to previous raise size (not necessarily previous bet size).

Calculating Pot Sized Raise = Pretend we make the call and then look at the total pot. This is the raise amount.

Is the action still open? = Only if we have faced at least one full sized raise since we bet.