Alright, so effective stack sizes are determined by the amount of bb in the shortstack, so far I am with you. But does the effective stack size stay the same in a single the hand? Let me try to explain.
So, let's say Hero 25 bb, Villain 25bb
In the first hand of hu hyper the effective stack size should be 24bb, since the one in the BB already posted a big blind, and if the BU min.raises than ess should be 23.5, and than if the big blind 3bs to 5bb, then the ess should be 20.5. What I am trying to ask here is, does the ess stay the same it was in the beggining of the hand, or does it change as soon as someone bets, on the flop, river etc.
[quote]ess=effective stack size[/quote]
The reason I am asking this, is because this equation (stack-1)/(2*stack)=equity needed facing an OP. First of all the problem with my reasoning in this equation is that if villain shoves than the ess should be 0bb(since he's got none left) and also if I already invested 1bb(I'm bb) then the effective stack sizes can't be 24bb to make this equation work since then I'm only obliged to call off when I have 50% equity, which is wrong.
[quote]stack in the equation is btw ess[/quote]
So to my question again, does the ess stay the same during a single hand, even after multiple bets on the flop, river etc?
Thanks
It's easy. The effective stack size is the most amount of chips which potentially could be added to the pot at any one time.
So if by the river you have nearly got him all in on the first hand with your royal flush and he has only one big blind left to play with you have reduced the effective stack size to one. Which is not going to be very effective for him given how pot committed he has become.
Our ess we usually use in order to determ how deep we are, what on the other hand, will help us to define our implied odds. Once you are postflop your ess is still existing but things like immediate pot odds and spr (stack pot ratio) are what we are using now. If you are the short stack and only have 18bbs left at the flop you cannot build a strategy based on that information, because the conditions (pot size etc.) are not known yet. Preflop you can build a (default) strategy around your ess.
Post flop you have other tools and stats you will use and in those stats the (current) ess only will be one of many factors that need to be considerd.
Hi.
Effective stack (S) is the maximum that can be won/lost during a hand.
Heads up, S = min (herostack, villainstack)
Effective stacks are calculated before the blinds are posted.
At the start of a hyper turbo you are 500/20 = 25 BB deep
The maximum size of the pot is 2 * S = 2 * 25 = 50 BB
@ 25BB when facing an open shove OOP you need 48% equity vs villain's open shoving range.
Calc worked through here:
http://www.husng.com/content/basic-math
Effective stacks are calculated at a single reference point (before blinds are posted) and so do not change over the hand.
As Barrin said it is used primarily as a preflop metric to help decide your best play.
As S decreases, your implied odds decrease because there is less money left behind on future streets.
Correspondingly, hands like 9x8x which benefit from implied odds are more valuable at larger effective stacks.
Hands like Ax3y go up in value as S becomes very short because it has good hot/cold preflop equity and stacks will being getting all in preflop with no opportunity to realise implied expectation postflop.
The analogous post flop metric is the stack to pot ratio (SPR), primarily used to factor pot-committment thresholds into your betting & bet sizing decisions.
That said, ideally your preflop decisions incorporate your plan for the rest of the hand and the effect your pre-flop actions have on your flop SPR at different effective stack depths.