SnG Coinflipping

[wtf5]

Hi, I have just started playing turbo sngs and am getting used to this new style of play (especially calling ranges on the bubble!)

i was working out how equity changes when you are coinflipping and was rather shocked with the results. If i have made an error please post and correct me, im knew to sngs and don't know that much yet [img]/images/graemlins/smile.gif[/img]

Premise: Early levels (10/20), everyone has 1,500, 10 people and you are dealth A,K.

Someone raises in EP to 100 and u repop to 300 total. it gets folded round to EP who shoves and shows Q,Qs.

Theory: probability of you winning * chip equity after winning > chip equity if you fold....then the move is +$ E(V)

so A,K vs Q,Q:

equity (%) win (%) tie (%)
Hand 1: 43.9439 % 43.73% 00.21% { AKs, AKo }
Hand 2: 56.0561 % 55.84% 00.21% { QQ }

equity: (calculated through http://sharnett.bol.ucla.edu/ICM/ICM.html )

Equity when folding is: 8.14% of total prize pool.

Equity after winning with 3030 is: 18.6%

18.6% * 43.73% = 8.13378%

So calling the shove is actually -$E(V) (barely) and in fact calling loses me 0.7 of a cent.

Are thoughts?

[Unknown Soldier]

Your math is fine.

In game though you won't know what cards he has, just a range. that will depend on the player. If he's loose he might be doing this with AQ+ 99+. In that case your equity is pretty much 50% so the call is +EV

If he's tight however, his range might be AKs QQ+ and your equity is 34.4%. So this is clearly -$EV

There are other factors to consider though. Is it worth it to push these small edges in a tournament so early? Let's say you have AKs instead of AK now the call is +$EV if he shows QQ, but it's still a small edge. You will probably be better off waiting for a better opportunity to get your chips in. It will depend on the competition. If your playing a bunch of idiots then fold. If your playing against world champions then call.

[wtf5]

Thanks for ur response tmwstw but the post wasn't erally about this actually happening. In this example (without knowing the villains hand) i would call all day in the SnGs i play (20 dollar) because i no i crush villains range.

The example i think serves to show that if ur calling an allin at any point barring the bubble in a SnG with a medium stack you need to either:

A) crush the villains pushing range

B) have a substancial amount of dead money in the pot calling with hand that doesnt crush villain range.

do you agree?

[Unknown Soldier]

Yes I agree. It comes down to not risking all of your money on small edges, but waiting untill you have a bigger one. Like "A" and "B"

[fraac]

At 20 dollar turbo sngs, most of your edge comes from squashing preflop limpy weakness in opponents. I like to double- and triple-up early on to maintain a large preflop advantage until the 300-600 level, especially as I'm favourite in a 'coinflip' when calling anyone wild enough to push in the first few levels (AQ+ any pair, is +EV until 100-200).

It's one of those freak examples where chips increase in value as you get more of them.

[Shandrax]

Calling an all-in as an underdog when the blinds are insignificant is usually -EV. So this outcome is not surprising at all.

[pzhon]

It sounds like you are overstating the importance of avoiding coinflips, a common error.

The difference between an even wager and AK vs. QQ is almost twice as large as the effect of the tournament prize structure, which changes your calling point from about 40% to about 43.7%. It would be a very clear call with QQ vs. AK. According to your calculations, incorrectly folding with QQ would cost you more than incorrectly calling with AK 100 times. It would also be a clear call with AK versus 22.

By the way, you made some mistakes in your calculation. You used the probability of winning rather than the equity, hence you counted ties as losses. The 0.43% ties turn the situation you describe into a call, according to the ICM. Also, it's unreasonable to give yourself a range of AKo,AKs. You should know whether your hand is suited, and it would make the difference here.