Help a math donkey figure out some preflop Omaha calculations (4bet pot itt)

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Help a math donkey figure out some preflop Omaha calculations (4bet pot itt)

Hey guys,

In a session today I ran into a spot where my gut feeling told me that the villain made a mathematical mistake. Being relatively incompetent in math I'm looking for some pointers in how to figure spots like these out.

Stacks are 147.80 BB deep. It's 5PLO 6max

Villain opens Qd Kd Jh 10c UTG to 3.40BB, it folds to Hero on the button who 3bets AxAx5dTd to 11.60. Villain being an aggressive 'regular' decides to 4bet seeing as he has the premium rundown and a suit to go with it. Furthermore Hero has probably been spotted 3betting non-AA some times. I guess the hand is probably slightly harder to play OOP.

Villain 4bets to 36.20 BB, hero makes it 110 BB and this for me is when the fun begins for discussion.

Assuming villains point of view there is no doubt hero has aces. He could play good kings similarly but the fact that we have a king and he does not seem worried about AA, it's AA.

If we jam we'll play a 300BB pot with around 37% equity against random aces. Since we've already put in 36.20 BB we're getting a good price on that play, and so its probably at this point fine. The question that this entire thread builds on is; Can we call and make more money than we can 'lose' by shoving?

My gut instinct as hero was that hero in the hand leaves too little behind for us to gain some kind of edge by calling here. So the question I went to research was, are we better off shipping it pre or calling?

This is the rudimentary math I did:

36.20->110

BB to call = 73.80

Pot odds: 147.60/73.80 = 2:1 = 33% breaks even

Equity vs range: 37.97% = call/get it in

To be played for on the flop: 37.80 BB

Future Pot odds: 221.40/37.80 = 17% for breakeven

I then went onto ProPokerTools and plugged in our hand vs AA** and found that we flop greater than 17% equity on roughly 67% of flops. This means that we fold and lose 110 BB 1/3 of the time.

I also looked at how often the hand had more than 50% equity, and this happens less than 30% of the time.

And thats how far I got, I can't seem to evaluate the play numerically. Losing 110BB 1/3 of the time while we have less than 50% equity 67% of flops the times we do get it in seems pretty bad? Help a new player out here :-)

I guess the question, rephrases is how can I evaluate the spot whether I should be jamming pre or just calling if I were in the same situation and what are the cutoffs? Can the villain call with his QJTK if I had 25bb behind, 10, 57? where's the breakpoint.

Thanks for reading my wall of text and helping me out!


9 Comments

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Chris B 11 years, 9 months ago

I can see I made a slight mistake by not adding the hero's 37.80BB to the flop pot, which changes the equity required to stack off down to 15% although it does not change the equity on the PPT graph. We still only get more than 15% equity 67% of the time.

jonna102 11 years, 9 months ago

I guess villain can call and fold if the flop comes 234r or 552.  Thing is, there won't be all that many flops where he doesn't have 15% or better.  Even on 568 with backdoor diamonds he pretty much has the equity to call it off.  When I run it in PPT I get 75% flops with <15% equity, I don't know why we get different results there. 

The argument for shoving instead of calling is if V. is not super sharp with equities.  It's going to be very marginal in some spots and if he thinks he might make some mistakes he might just as well shove preflop and avoid those mistakes.

And if there's any question of you having AA when you 5-bet, V should just obv get it in pre.

That said...  even if you would be wide here, V. has put in 36BB and is now looking at playing for another 110BB as a severe underdog.  In some situations he may have a break even play by getting it in, but given the rake at these stakes I would expect it to actually be a losing play. 

It probably makes sense to look at the whole situation here.  If all the money goes in preflop, V. plays for his whole stack as a 2:1 dog (roughly).  That just won't be a winning play, regardless of what odds he's getting when you 5-bet.  His biggest mistake is 4-betting this hand.  This could be a good play in some situations, but this just isn't one of them.  

Tom Coldwell 11 years, 9 months ago
Two things:

1) You get different results on the PPT sims 'cas they aren't exhaustive so you had different samples. In fact, there's quite a huge variability in the results that graphing HvR will give you (just play around changing the offsuit J and T to different combos of offsuit and see how the graph looks different).

2) Re: stacking off if there's any hope not AA, this isn't quite true. If villain believes hero's range is only AA or KK, he actually performs worse than against just AA for obvious reasons.

I'd also like to note that I don't necessarily agree that his 4-bet is a mistake. We haven't got the information to decide that imo, but including hands like KQJTss in a 4-betting range isn't completely unreasonable (although I guess I tend towards 4-betting double-suited + slightly lower hands where possible so that I do better when they have AA which I don't block - JT98ds being a very good one). If villain thought hero was 3-betting really wide though, he's played his hand fine.


Tom Coldwell 11 years, 9 months ago

Yeah, your math isn't correct. First things first, the equity required to stack off isn't 33%, it's around 37.5. You calculate this by diving money behind by total pot once all in - (147.8-36.2)/296.5 = 111.6/296.5 = 37.6%. This obviously makes a difference given his hand only has about 37.92% against AA and therefore stands to make a tiny profit of around 1bb. Given rake, jamming will actually be a slightly losing play.

However, calling shows a pretty solid profit. If we stack off every time we have the necessary equity (which is 12.7% - 37.8/296.5), we will be putting it in about 84% of the time w/ an average equity of around 48% (I say around 'cas PPT sims like this aren't perfectly precise and have a decent margin of error). On that assumption, the 84% of the time villain stacks off postflop, he'll make a 31bb profit on the call (which was 73.8bbs given 36.2 was already in the middle). However, the 16% of the time he has to fold, he'll lose the 73.8 he just put in - conceptually different to the assumption you were making 'cas you weren't treating the initial 4-bet as lost/no longer villain's which you should have been given it's already in the pot. If we multiply these wins and losses by their frequencies (0.84 and 0.16 respectively) and add them together, we are given actual profit on the call: 14.5bbs.

This shows that calling performs significantly better than shoving would have done, but he'll still show a net loss in the hand (given that 14.5bb profit comes after he'd already lost 36.2bbs 4-betting). Therefore, when he checks his PokerTracker for spots similar to this, he'll find himself losing, on average, over 20bbs (your profit w/ AA). However, that doesn't mean he made a mistake continuing after the 5-bet because had he not done, he would have sacrificed the 36.2 he'd put out there which would have been a far greater loss than the one he incurred playing to the finish.

Conclusion: His call was the clearly the best play open to him.

Philly 11 years, 9 months ago

very good post! Never saw it from the angle "loosing 20bb is worse than 36" because intuitively folding to the 5 bet is 0EV (what it obv. is, but here we compare it to the net loss of the 4bet if we fold)

But where do you get the numbers "...we will be putting it in about 84% of the time w/ an average equity of around 48%..." from?

Tom Coldwell 11 years, 9 months ago
I used the PPT graphing simulation which is where I got the 84% from. The 48 requires a little bit of voodoo math on the generated graph to work out the average equity. If you're interested in this sort of thing, I made a video a little while back which takes you through this sort of calculation step-by-step: Calling 4-bets


TianYuan 11 years, 9 months ago
For required equity you should divide by the final pot size, so we get 37.8/297.10 = 12.72%

Using odds oracle:

How often does player_1 have hand vs range equity of at least 12.72% on the flop -> 77.8%
Equity stats -> Require that -> Player_1 -> Have hand vs range equity of at least 12.72 on the flop -> 46%

For an EV of about 3bb on the call... However as Tom said, there's a lot of fluctuation in Odds Oracle / PPT sims, so the true EV is more likely somewhere between breakeven and this. Possibly losing with rake factored in.

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