Deliberately walking into a Surrender Trap

I recently played a final hand which worked out well for me, but in which my strategy may have been a bit suspect. I'm not sure if it was an act of genius or idiocy. I'd appreciate any thoughts ....

Two players.
min bet: 100
max bet: 1000
no doubling for less

BR1: 1888, bets 944
BR2 (me): 1045

BR1 was not a tournament expert, but not a total novice either. It seemed clear that the bet was chosen simply as half the BR, rather than an attempt to lay a surrender trap, but there was still the likelihood that if I bet 100 the possibility of surrender might become obvious to BR1.

I bet 200 on the basis that I would surrender if BR1 did not, and I would double down on any hand if BR1 did surrender. ( BR1's surrender total is 1416, and I could dd to 1445.)

Was my bet a good one or would it still have been better to bet big and play for a swing?

As it happened, the cards were dealt as follows -
dealer: 2
BR1: 2,T
BR2: 7,3

The fact that I had a BS double down hand possibly helped prevent BR1 from surrendering, so I was able to take back the low and the dealer helpfully did not bust.

 

I think it was a great bet. It's a calculated risk, and it sucks to lose when you feel you didn't give yourself a chance -- but sometimes it is okay to play along with the surrender trap if, as in this case, you think your opponent just overbet. Here you had two scenarios: (1) he doesn't surrender and (2) he surrenders and you can still dd and win. The other option is you need a swing, which as we know is <20%. Assuming you had a good read on your opponent and thought it was at least X% likely he wouldn't surrender, this was a great move.

We could solve for X relatively easily by running the scenarios, but I think it will be surprisingly low -- like 30-40%.

 

Thanks guys

My feeling, right or wrong, was that my opponent was unlikely to surrender, whatever hand I was dealt. The fact that I got a strong double down hand just makes it harder to know if I was right, because it may have been a factor in the descion-making process.

So I was expecting (or at least hoping for) the opportunity to take the low by surrendering, with the double-down in reserve as my get-out-of-jail card.

I'm not sure it would be all that easy to run the scenarios, at least without computer assistance. Don't you have to go through every possible combination of BR1/BR2 player hands, plus dealer upcard? Surrender won't always be the best option for BR1; their chance of winning/pushing the hand may be greater than my chance of losing a dd.

If I were BR1, I'm sure I'd be capable of making a mistake in this scenario, which is perhaps another plus point for the 200 bet.

In the extreme case, if BR1 elects to surrender any hand other than a BJ, my chances presumably are around 0.3 (i.e. the chance of winning a double with two random cards).

I'd be curious to know how it pans out with other BR1 strategies; e.g, stand on any 19,20,21 first two cards, otherwise surrender. That's probably the way I'd have played it as BR1 (with 20s to act!), but does anyone know how close that is to optimal?

 

nice play

Colin,

I like your play, regardless of what the numbers say (and they are good, I will have some in the next post).
You recognized a unique situation, you included your opponent probable behavior, run scenarios of other possible plays, and in conclusion you used your intuition (which is based/built on previous tourney experiences and theoretical analyses) to make unusual play but one you believed have had the best chances to succeed. This on itself sounds like fun that we seek by participating in tournaments.

S. Yama

 

unconfortable comparison

Side comments on surrender play if BR1 plays optimally after “overbetting” his lead, but can surrender to advance if his opponent doesn’t win double bet, just like Colin described.

Optimal BR1 play is to surrender if the chance of losing his hand is greater than BR2’s chance of winning double bet.

This sounds relatively easy, right?
But it is counterintuitive because we are dealing with negative result on one side and positive on the other. The same principle could be stated as:
BR1 should not surrender if his chance of winning is greater than his opponent losing his forced double bet.
Unless we practice with the numbers beforehand, this will be very confusing when it comes to real play.

Let’s have some examples. Starting with dealer’s upcard 2.
If we have a stiff hand, we don’t lose only if the dealer breaks, so does the opponent doubling on hands total four to six. It is a tie decision, unless you count cards or you count on the opponent making a mistake not doubling after you surrendered. So we surrender all stiff hands.
If we have seventeen and stand we win or push (thus advance) 48.6% of the times, so we surrender if the opponent chances of winning a double are less than that. Our opponent's doubling on total 9 succeeds slightly less than that, so we surrender against opponent’s total 9 or less (taking a better chance – he has to win the double) and stay against 10 to 11 (he w would win double more often than we push or lose our hand). We also surrender against the opponent’s stiff hands, as his chances of winning double are worse than our chance of 48.6%.
If we have eighteen and stand we win or push (thus advance) 62.2% of the times, so we surrender if the opponent chances of not winning a double are greater than that. Now, doubling on total 9 fails less than that, so we don’t surrender, but against opponent’s total 8 or less we do surrender, and we stay against opponent’s 9 to 11. We surrender against the opponent’s stiffs.
If we have nineteen and stand we win or push (thus advance) 75.4% of the times, so we surrender if the opponent chances of winning a double are worse than 24.6%. We would surrender only against the opponent hands of 16 to 19.

This may be very confusing (and still is to me), because we usually surrender more when our hands are better versus the opponent’s hands harder to win.

Still fun, right?

S. Yama

 

Accidentally creating a surrender trap

Here's one from the final hand of the first Durant (OK) tournament last week - the seasoned players here will likely get a chuckle out of it. Max bet 50K in 1K increments, min 5K, BJ = 3:2, DOA, DAS except Aces, surrender available.
Only three players left, 1st is $500 plus a free seat in the finals, 2nd $250, 3rd $125.

In betting order:
Me 89K
Dead Meat 24K
Good Player 61K ("Good" but not excellent)

I bet 34K, exactly covers Good Player's possible all-in DD plus one chip. Dead Meat all-in. Good Player startles the hell out of me by only betting 5K. Cards come out but I'm not paying much attention, am busily counting and re-counting chip stacks because I can't believe what Good Player just did. She doesn't get a pair so there is no split possibilities, but can DD to 71K. I finally believed what I was seeing and surrendered my 34K bet. 89K - 17K = 72K. Wish I could honestly say that I structured the bet like that on purpose, but I'd be fibbing.

She told me later that she was protecting 2nd place money, and that she'd also realized a lose-lose between her and I would give her 1st by 1K. She didn't realize that she'd handed me a surrender trap until she noticed how long I was taking to act on my hand.

 

I'm glad you say that. Makes me feel a bit better about my own confusion.

I've never really made the surrender trap part of my armoury; I'd certainly be reluctant to try it unless I can cover the opponent's dd, as I don't know how much I might cost myself by misplaying the resulting surrender-or-not quandary.

What would Good Player's best bet have been? I can see a few options, all of which include the possibility of finishing in a tie -

1. A bet of 12K covers your surrender and still locks out Dead Meat. It also presents the opportunity to surrender back to a total of 55K, tying with you if both lose.
   
2. A bet of 11K only ties with your surrender, but presents the opportunity to surrender back to a total of 55.5K, winning if both lose.
   
3. A bet of 6K requires a dd to cover your surrender, and ties if both lose without doubling.