Optimising Position to Establish an Opponent’s Range

Optimising Position to Establish an Opponent’s Range

Thursday, 11 August 2011

As almost all poker players know these days, position is key to gaining information from your opponent. The more information you have when the action comes to you, the better your decision making should be, and, in turn, the better your results should be. Paul Zimbler explains.

As almost all poker players know these days, position is key to gaining information from your opponent. The more information you have when the action comes to you, the better your decision making should be, and, in turn, the better your results should be. Playing in position allows you to establish an opponent’s range of possible holdings with greater detail. The following example displays how to use small bets in position to narrow down your opponent’s range throughout the course of the hand.Nine-handed deepstack MTT, middle-stage of tournament

Blinds 500/1,000 Average stack 100,000

Player 1; UTG+1; stack: 220,000; hand: AhJh
Player 2; HiJack; stack: 180,000; hand: 6c6s
YOU; BUTTON; stack: 250,000 QdQc
P1 raises 2.5 BB to 2,500
P2 calls
(All other players fold)
YOU reraise to 6,500
(Blinds fold)
P1 calls
P2 calls
Pot: 21,000

All three players involved in this pot have relatively deep stacks, so it’s unlikely that either of your opponents will get themselves committed to the pot without a top-band, premium hand like A-A or K-K. Many players will be sceptical of raises from the button and may think you are making a play with a wide range of hands.

Player 1’s raise from early position does indicate a lot of strength, but since you have woken up with Q-Q on the button, you can use your deep stack to raise here to inflate a pot in which you have position, potentially narrowing the field to heads up or even taking it down straight away.

So you raise to 6.5k. When Player 1 just flat calls, it’s less likely he has A-A, K-K as most players would prefer a 4-bet in this situation. Player 2 also flat calls, which could indicate a drawing hand that has been priced in for value in the multi-way pot, like suited connectors or a small pair with the intention of “set mining”.

FLOP: Kh10s8s
Player 1: Checks
Player 2: Checks
You: Bet 2/3 of the pot 14,000 (remaining stack)
P1 calls (remaining stack)
P2 folds
POT: 49,000

There is only one over-card to your Q-Q on the flop, but there are various straight draws and a flush draw. Both players check to you, probably expecting you to make a continuation bet. There is the danger that someone has checked a flopped set to you with the intention of raising, either on this round or a later round of betting. However, we do not want to give away free turn or river cards without at least gaining more information. We bet two thirds of the pot, 14k, which is a sizeable bet that should chase away backdoor flush draws, gut shot straight draws, some ace-high holdings and lower pairs that could hit trips or a sets on the next two cards. When Player 1 just calls our bet, it indicates he has a hand with which he wishes to see further cards, so a strong draw or 1 pair are both feasible holdings, and you no longer need to worry about Player 2 as he is no longer involved.

TURN: 6h
ACTION: P1: checks, You: bet 50% of pot 24.5k, P1: calls
POT: 98,000

Now there are two flush draws, but the six does not complete any straight draws. By betting the flop you managed to price out Player 2 who would have got lucky on the turn with a set.
When Player 1 does not use the option to re-raise us here it decreases the chance that he has improved as it is unlikely that he would let you see the river for free, which could complete the two flush draws. Because of the fact that that Player 1 has just called again, it looks like he is drawing and wants to see the river to try to hit an out, or possibly has a medium pair and is hoping that you are just semi bluffing with a flush and straight draw and intends to call you down light on the river if the flush and straight draws miss.

ACTION: P1: checks YOU: bet 50% of pot 49k  P1:Calls
POT: 196, 000 (You Win)

The J of clubs on the river appears to be a reasonably safe card for our hand as it does not complete either of the flush draws and most gutshot draws should have been bet out of the pot by now, therefore we can bet our hand for value. We now need to bet-size appropriately to get paid off from hands such as AhJh, Jh10h, 10h9h, 9-9 or 8-8 which are all possible holdings of Player 1. However be prepared to fold if re-raised as Player 1 may have been slow playing a set of tens, eights, rivered a set of jacks, or pot-controlling with A-K with the intention of check raising on the safe river card.

As the likelihood of the latter is small, due to the lack of aggression from Player 1 on the previous rounds of betting, we should optimise the value of our hand with a thin value bet. As Player 1 has hit a pair on the river and thinks we may be turning a semi-bluff into a bluff, he pays us off. By using a series of bets after our opponents have acted on each round of betting, you can gain valuable information as to where you are in the hand. You can make a good estimate to your opponents' holdings based on how they react to your bet. This information allows you to maximise the value of your hand in what otherwise could have been a marginal situation.

Tags: Paul Zimbler, Strategy