Does relative position matter if one player is face up?
Does relative position matter if one player is face up?
Scenario: Bob and Alice are playing a deepstacked cash game, heads-up to a flop. Bob flips over his hole cards on the flop. Both players play optimally based on the available information.
Question: If we reverse the positions (IP ↔ OOP), such that Bob and Alice are playing the same ranges but switch the relative positions, will their EV change? Why or why not?
---
Related question: Does positional advantage stem entirely from information asymmetry?
In this experiment, Bob's range is already narrowed down to one combo (their hand is face up), so Bob's actions don't give Alice more information about Bob's range.
5 Replies
I don't know about deepstacked, but I ran two pairs of sims (0.01% accuracy) for a 2 SPR situation which seems to show that EVs change with positions if we give Bob a face up drawing hand.
Interestingly, in the first pair of sims, the EV of being IP with the face up drawing hand is higher than being OOP.
But in the other pair, given a smaller betting option, the EV of being OOP is higher.
(In both pairs, the options vs bet is fold, call or shove)
1st pair of sims:
Spoiler
Face up drawing hand (JhTs) is OOP
EV = 1.954
EQR = 37.4%
Face up drawing hand is IP
EV = 2.077
EQR = 39.7%
2nd pair of sims:
Spoiler
Face up drawing hand is OOP
EV = 2.246
EQR = 43.0%
Face up drawing hand is IP
EV = 2.110
EQR = 40.4%
I haven't figured out exactly why, though, but I guess there's at least two types of uncertainties normally in play in poker:
* Uncertainty regarding relative hand strength. This incentives value-betting and bluffing.
Otherwise, value-betting a 100% equity hand would have the same EV as checking, as villain simply folds.
* Uncertainty regarding future actions
For example: When we are IP and are checked to, we know with 100% certainty that we can check behind or bet as we wish, but when we are OOP, we are uncertain whether IP will bet or check.
This uncertainty regarding future actions can also be seen in the AKQ toy game, where ranges are exactly the same, yet OOP and IP strategies are radically different.
Seems like an obvious yes. When Bob has utter trash that he is always folding, or a very strong hand that he is never folding, then perhaps it doesn't matter. But anytime Bob has a hand where he might want to bet but might not want to get raised, or wants to check but might not want to face a bet, position matters.
I don't know about deepstacked, but I ran two pairs of sims (0.01% accuracy) for a 2 SPR situation which seems to show that EVs change with positions if we give Bob a face up drawing hand.
Interestingly, in the first pair of sims, the EV of being IP with the face up drawing hand is higher than being OOP.
But in the other pair, given a smaller betting option, the EV of being OOP is higher.
(In both pairs, the options vs bet is fold, call or shove)
1st pair of sims:
Nice analysis, Zamadhi!
I came to a similar conclusion - position matters, (albeit not very much) when a player is face up.
Two things to consider:
1) Why is the positional advantage so small?
2) If both players are face up then position should not matter right? (Assuming pot limit or something to make it less trivial)
Seems like an obvious yes. When Bob has utter trash that he is always folding, or a very strong hand that he is never folding, then perhaps it doesn't matter. But anytime Bob has a hand where he might want to bet but might not want to get raised, or wants to check but might not want to face a bet, position matters.
Why those conditions specifically?
What is the underlying reason that having position is advantageous?
32o lost EV OOP because when IP you can check it back and see free turn every time. I guess as long as player without faceup range can't just bet range and force faceup hand to fold position will matter more or less.
If you put AA+ A4s vs JT then, imho, position won't matter. If you put AA+42o+32o vs TJ then it would matter more.
Extreme version of the main question would be:
Would position matter if Bob was playing with his cards face up and Alice was secretly playing blind (without looking at her cards) ?
I think it would still matter.
