Standard Field Sizes
Let's call the sum of the folded hands, that have the option of entering the side pot, 'the Unfold field'. We begin with the most common size of Unfold field, which, on an 8 handed table, is 5-6 players. This is because most main pots are raised or re-raised and the field size is thinned dramatically, unless the table is playing exceptionally loose/passive.
Let's assume that there is an Unfold field of 6 players and that each one has folded from the main pot with a range of the bottom 84% of hands that you can be dealt in Holdem. While it is true that each player in the Unfold field will have folded a different range in the main pot due to position and individual player tendencies, this should be a reasonable estimate for our purposes.
On a dry flop of , each player in the Unfold field will have less than one pair 64% of the time. Most hands miss most flops in this game and we have eliminated all pocket pairs from our opponents ranges from the fold they made in the main pot (this will be true fairly often in reality, though obviously not always) If each of our five opponents unfolds a pair or better on this flop, then each one remains folded 64% of the time. To find out how often we will take the side pot down from being the only Unfolder, we simply multiply these 'remains folded' possibilities together five times; once for each opponent.
0.64 x 0.64 x 0.64 x 0.64 x 0.64 = 0.11
We estimate that we will win the side pot 11% of the time right away by Unfolding our hand and no one else doing so. This is not spectacular, but it is a real boost to our EV and makes the situation a very profitable Unfold wherever our likely equity vs. our opponents' Unfold ranges is reasonable enough to approach breaking even those times when we have to see the turn and river.
Let's take an example now and see what happens when we have to contend with one other player after Unfolding a meager K3o on . If we assume that our opponent is Unfolding any pair and never a gutshot straight draw, then our equity is an impressive 32.5%. All we have done is called one pot-sized bet to realise all of our equity for no additional cost (remember in Unfold we see the turn and river for the price of the Unfold pot.) This means we have got 2:1 on our money. In order to break even in a world where we had no chance of winning the Unfold pot by our opponents all remaining folded, we would need 33.33% equity to Unfold and would be very slightly losing from Unfolding this hand. However, given that we won the entire side pot uncontested 11% of the time, we have clearly made a profitable Unfold overall.
We can extrapolate form this that, even in a 6 handed field it is correct to Unfold small pieces of the flop. If our opponents fail to realise this, then they might unfold too selectively, which will bring that 11% uncontested win frequency upwards and persuade us to Unfold some very dubious hand indeed!
The table has dropped to 6-handed and three of our opponents are doing battle in the main pot. We and our two other foes are deciding whether or not to unfold on a flop of . Our hand is a lowly gut shot straight draw: to be exact.
Each player, again assuming 84% pre-flop folding ranges, will have flopped less than one pair here 81% of the time, will have made a pair of kings 11% of the time, and will have trips just 7.5% of the time. If our opponents are not careful, they could each end up remaining folded something like 80% of the time (assuming that they never remain folded with JT). This will mean that both players could remain folded 64% of the time and in such a world we would want to Unfold any two cards and would profit immensely from doing so.
Even if we had 0% equity when we were forced to go to showdown (which is impossible) we would still only need to take down the Unfold pot 50% of the time to break even. Our will have 8 clean outs against a pair and more against ace-high hands. Our equity is going to be a very comfortable 16% against a hand like K,7 offsuit.
The result of this analysis is that our opponents have to Unfold very weak hands indeed to stop us from printing money by Unfolding any two cards. If they do that, then our equity with hands like J9o goes up significantly. Against A4o we have 35% and are making money by Unfolding at a price of 2:1 even if our opponent never remains folded!
So as it happens, in this size of field, J9o is such a mandatory Unfold that we don't even need to think about it.
The fascinating part of playing this game in a very small Unfold field is the incredibly loose standard for Unfolding. I strongly expect that the majority of your weaker opponents will not understand pot odds properly and will Unfold based simply on their absolute hand strength. This will create a situation where you can take down the side pot uncontested a ludicrous amount of the time and slowly bleed the table dry by Unfolding your sweet nothing over and over again.
Folding in the First Place
In poker, as we have known it up until now, there has been no incentive to fold. We have always folded in the standard format of the game, not to win something, but to minimise what we are losing and avoid putting chips into the pot in a –EV manner. In Unfold, we are promised a share of the Unfold antes every time we press the fold button in the first place. This means that the close spot where J,7 suited is almost good enough to open in the cut-off, and might be a break even open-raise, is now a mandatory fold! We used to compare the EV of playing a hand to 0. Now, in this format, we compare it to a much higher value that comes from the combination of taking down uncontested Unfold pots and winning contested ones.
Of course, this new dynamic, increases fold equity in the main pot and means that a steal will get through a lot more often than in regular formats with no compensation for folding. This can go full circle and persuade us to steal wider again if our opponents have realised that they need to tighten up.
One other very lucrative route for a big blind, however, when facing a steal, is to re-raise more frequently, substituting some standard calls in regular no limit holdem for 3-bets. As the pre-flop opener is incentivized to err on the side of folding rather than calling where the decision would be a close one, a 3-bet might find a higher degree of fold equity than in normal games. This fact can certainly create its own meta-game where players react to pre-flop raises with much more of a raise or fold strategy, but in turn, tailor their raising ranges to expect such a response from their opponent in the first place.