Refer to the Power Number when you are short stack in an MTT


The Power Number or how to play short stack in an MTT in early or middle stage?

Power number

You are playing an MTT and are off to a bad start, the field is still big and with only 11BB left you are starting to lose hope. Players at the table are agressive and prevent you to find a nice spot. Blinds and antes are eating up what remains of your stack. Next time everyone folds before you are determined to go all-in preflop with any decent hand. The occasion happens and you shove your stack with T7 suited. You face a snap call from the big blind which reveals KK…You are out and keep wondering if you made the right move or not, if you should have waited for another hand. Where you right to risk your tournament at this stage? Lets find out.
The power number is a concept that allows you to play a game which is mathematically unsuable by your opponents. The short stack status is so specific and so « theorytically straight forward » that all spots have been studied and assessed and synthetized in this model.
First you need to calculate your M-factor. M equals the number of rounds you can survive in a situation where you would decide to stop playing any hand (factoring in SB, BB and antes if they do apply). Hence M = your stack / CPR (or cost per round). M = your stack / (SB + BB + number of players at the table x antes). Let’s assume our M is 4,5.
If your 3 < M < 8 the power number model enables you to determine if your hand is strong enough to sustain a profitable all-in move (assuming that all players before you have folded).
After having calculated your M you need to calculate your power number at « equilibrium », the PNe meaning the minimal PN you need to justify an all-in.
PNe = M x number of players to speak.
Last you need to refer to the below table which provides the PN of all starting hands. If the PN of your starting hand is superior to the PNe you can go all-in and will be profitable in the long run. If PN < PNe you have to fold.
Going all-in with T7s was the right call.
Remember this is a statistical model (very robust) but it assumes that all players at the table play in an optimal manner (which is rarely true). You might need to adapt it slightly depending on your image at the table and your opponents profile.
NB: this model loses its interest as you get closer to the money (due to the change in the distribution of the prizepool). You will then use the Independent Chip Model (ICM) since too many parameters need to be taken into account when reaching the bubble.

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