How Poker Players Think About Bet-Sizing

Players talk about bet-sizing in relation to the size of the pot. The purpose of thinking about bet-sizing in relation to the pot is to understand the odds you lay to your opponent to continue in the hand.

Examples:

• You bet pot, your opponent receives odds of 2:1.
• You bet 3/4 pot, your opponent receives odds of 2.3:1
• You bet 1/2 pot, your opponent receives odds of 3:1
• You bet 1/4 pot, your opponent receives odds of 5:1

Speaking of bets in terms of x times the big blind is of little, if any, use. Understanding how to create a proper bet size is important—and sometimes a bit tricky.

Leading with a bet postflop: When a player is the first to bet into a postflop pot, the logic is simple. E.g., a pot is $10 on the flop. A pot bet is $10, and your opponent gets $20 to $10, offering him 2:1. You make a half pot bet of $5 into the $10 pot, and your opponent receives $15 to $5, offering him 3:1. Etc. Creating the sizing is simple in these situations.

Raising a bet postflop: Raising after an opponent bets requires more work. Imagine a pot is $10, and your opponent bets $5. The pot is $15, and the action is on you. You wish to offer your opponent 2:1 and therefore need to make a pot-size bet. How do you determine the sizing? There are various methods, however, this is the method I find the simplest.

1. Determine the size of the pot if you would just call.
2. Multiply the result of #1 by the percent of the pot you wish to raise. (½, ¾, 1)
3. 3. Add the opponent’s bet to the result of #2.

In our example of a $10 pot and the opponent bet $5:

1. If we just called, the pot would be $20
2. We wish to make a pot-size raise, which is a multiplier of 1. $20 * 1 = $20
3. The opponent bet $5. $20 + $5 = $25.

A pot-size raise in this situation is to put in $25. The pot is now $40, and the opponent must call $20 to continue; he’s getting 2:1.

If we wish to make a 1/2 pot bet, we change step 2.

1. If we just called, the pot would be $20.
2. We wish to make a 1/2 pot raise, which is a multiplier of 0.5. $20 * 0.5 = $10
3. The opponent bet $5. $10 + 5 = $15

A 1/2 pot raise is putting in $15. The pot is now $30, and the opponent must call $10 to continue; he’s getting 3:1.

Raising a bet postflop in a multiway hand: Multiway pots require us to qualify our definition of bet-sizing. With our sizing, we offer pot odds to the last opponent who put money in the hand. You also look at the bet size of the last opponent for step 3. An example:

The pot is $10 on the flop. You’re in the hand with Bob and Sue. Bob bets $5, and Sue raises to $25. The action is on you, and you wish to make a ½ pot raise.

1. Should you just call, the pot would be $65.
2. You wish to make a 1/2 pot raise. $65 * 0.5 = $32.50
3. Sue’s bet was $25 (she was the last person to put money in the pot). $25 + $32.50 = $57.50

Let’s assume Bob folds. The action gets back to Sue. The pot is $97.50, and Sue must call $32.50. She’s getting 3:1, which is what we hoped to accomplish with a 1/2 pot bet. Notice our bet-sizing doesn’t offer Bob 3:1. When the action comes to Bob, the pot is $97.50 and he must call $52.50—obviously much worse odds for Bob. But our bet-sizing is aimed at the last player to put money in the pot.

Opening the pot preflop: The trick to understanding sizing preflop is to realize the big blind is the last person to put money in the pot. The sizing is aimed at the big blind. If you wish to open a pot preflop with a pot-size raise, you aim to offer the big blind 2:1.

Let’s use a $0.5/$1 game. Action folds to you on the button, and you wish to make a pot-size open.

1. Should you just call, the pot would be $2.50.
2. The multiplier is 1. $2.50
3. The last bet was $1 (the big blind). $2.50 + $1 = $3.50

Opening with a pot-size raise is $3.50. Action comes to the big blind, the pot is $5, and he must call $2.50. This gives him odds of 2:1. Obviously the odds are worse for the small blind.

Multiway preflop raising is identical to postflop multiway raising. You offer odds to the last person who put money in the pot. Imagine a $2/$4 game, and you’re on the button. Under the gun opens for $12. The action folds to you on the button and you wish to make a 3/4 pot raise.

1. Should you just call, the pot would be $30.
2. The multiplier is 0.75. $30 * 0.75 = $22.50
3. Under the gun raised to $12. $22.50 + $12 = $34.50

If both blinds fold, action comes to under the gun and the pot is $52.50. He must call $22.50 to continue. $52.50:$22.50 is 2.33:1, which is what we’re after with a 3/4 pot raise.

Following these three steps removes confusion for action in the blinds as well. For example, action folds to the small blind in a $1/$2 game. The small blind wishes to make a pot-size raise and offer the big blind 2:1.

1. Should the small blind just call, the pot would be $4.
2. The multiplier is 1. $4
3. The big blind (last person to put in money) is $2. $4 + $2 = $6

The small blind raises to $6 total (putting in $5 more). The pot is $8, and the big blind must put in $4 more, odds of 2:1.

A final example. A $5/$10 game. Action folds to the button who opens for $20. The small blind wishes to make a 1/3 pot raise and offer the button 4:1.

1. Should the small blind just call, the pot would be $50.
2. The multiplier is 0.33 (rounding). $50 * 0.33 = $16.50
3. The button’s bet (last one putting money in the pot) was $20. $20 + $16.50 = $36.50

Assuming the big blind folds, after we do the math, we see the button would get about 4:1 with this sizing (off a bit because of the rounding).

Obviously, we must always check to make sure a given bet size is a legal raise size. The options I gave Kiril when I was in Bulgaria will almost always be a legal raise size. Here are the buttons for the client:

Min-betting and min-raising: A minbet is the smallest legal amount a player may bet. A minraise is the smallest legal amount a player may raise. The only exception is when a player does not have enough money in his stack to make the legal bet/raise.

In no-limit and pot-limit, a minbet is always the size of the big blind. The minimum raise is the amount of the last bet or raise. The definition of raise sometimes causes confusion.

Imagine Bob bets $5 and Sue raises to $20. When we say “Sue raises to $20” we mean Sue put a total of $20 in as her wager. This $20 includes the call of Bob’s $5 and an additional $15 raise. In this sense, someone can say Sue raised $15. While this is true (and important to understand), poker clients simply use “Raise” as the total amount of chips a player is putting in with his/her wager. In this case, Sue’s client would read “Raise To $20”.

Let’s say Sue does raise to $20, and the action is now on Bob. Bob can call for $15. However, if he wishes to minraise, the minraise amount is raising to $35. This is Sue’s bet of $20 plus Sue’s raise of $15. Bob’s client would read “Raise to $35”. This is NOT $35 on top of the $5 Bob already put in the pot. When Bob finishes reraising, he will have put $35 total in the pot on this street. (Another way to think about this is Bob must call the $15 from Sue and then his minraise is $15; a total of $30. Therefore, Bob is putting in $30 more than his previous bet. Clients simplify this to “Raise To x” where x is the total amount the player is putting in the pot on the current street.)

When a player does not have enough money to make a legal raise:

If a player can raise a bet but does not have enough money to make a legal raise, he may still go all-in. A side pot is created and his raise is considered a call, which means his raise does not open the betting for other players to reraise.

Example: Bob bets $5. Sue raises to $20. Joe goes all-in with his $30. A minraise for Joe is $35; however, he didn’t have that much. Bob calls for $25 more. Action is back on Sue. Sue cannot raise again. The betting is not open because Joe’s all-in is considered a call. Therefore, Sue can only call for $10 or fold.