[sirgasleak]

Looks like a pure ICM play – with the tiny stack in the BB, SB knows BTN has to fold basically everything. Losing 60 of his chip-leading 80bb stack would be an absolute disaster. The risk-reward is so lopsided that this spot may be equivalent to a satellite stone bubble situation.

Would it work in lower stakes? Maybe, if you’re playing with players who have at least a basic awareness of ICM.

[imalouigi]

If the stacks were reversed, this makes complete sense. However, since button covers SB (and not the other way around), isn’t this ICM suicide for SB? I don’t understand this play and am very curious to have someone give some insight/rationale for the shove.

Wouldn’t a raise to 5 bb make more sense? It would price in the BB and then the button would overcall and (implicit collusion) they can check it down to the river?

This spot has me scratching my head and now I want to hear more!

[tvstensby]

I have tried to use HRC to study this spot (beta version using ICM mode and postflop engine). I have attached images with SB strategies and the bubble factors.

Scenario 1: Several bet sizes for both 3-bets and 4-bets. Calling and overcalling allowed.

• Open: 2bb.
• 3-bet: 5bb, 11bb and all-in.
• 4-bet: 13bb and all-in.

BTN opens 51.4% of the time. In this scenario the SB does not use the all-in 3-bet sizing at all, but calls 21.6%, raises to 11bb 5.1% and raises to 5bb 0.9%.

One reason why the 5bb raise is used infrequently might be to deny the BTN the possibility to close the action when the BB decides to go all-in. When SB calls the open, then BB can open the betting again and SB gets to act last after the BTN.

Scenario 2: Same as scenario 1, but with BTN and SB stacks reversed.

When the second largest stack is on the BTN the opening range goes down to 40.4%. The SB then calls less (18.9%) and 3-bets more (11.9% to 11bb, 3.9% to 5bb and 0.5% all-in).

Even though the biggest stack can apply the most ICM pressure the solver prefers to fold more. Fighting the second biggest stack is not what the biggest stack wants to do.

Scenario 3: Removed the 5bb 3-bet and the 13bb 4-bet.
The idea behind this scenario is to see if the all-in 3-bet is used more if the players have fewer options to choose from. In this scenario the assumption is that the SB prefers isolation raises, which will cause the 4-bet from the BTN to be all-in.

The SB strategy only changes slightly in this case, the all-in 3-bet is now used 1.1% of the time, calling is 23.0% and raising to 11bb is 3.5%.

Scenario 4: Removing even more options, only use all-in as 3-bets and 4-bets.

If we remove even more options the use of the all-in bets increases to 3.8%, while calling reduces to 12.9%. SB is also folding more than in previous scenarios.

Observations/conclusions:

• Going all-in with AQs is not the preferred action by the solver in this situation.
• However, in a simplified scenario AQs is used with some frequency.

Personally I am a bit surprised that the SB made this play, but perhaps making plays like this is required at this level. It definitely sends a message to the other players.<div>

<div><div>

PS: I have not watched the Poker Masters coverage, so I have no idea what the table dynamic was when this hand was played.

</div></div></div>