Basic maths: 3bet vs villains' F3B %

Let's keep it simple and say that someone has opened on the BTN to 3bb, and we're in the BB. If our 3bet would be to raise it up to 10bb then is the following true - assuming a fold is a win and a call or raise is a loss just to keep it simple.

When we lose = -9bb
When we win = +4.5bb

odds on a bet = amtlost/(amtwon+amtlost), therefore

9/(4.5+9) = .67 (or 67%).

So if someone folds to a 3bet on the button over 67% we show an instaprofit in the long term given these bet sizes?

yes

but it'll take a long time for stats to converge for f3b so take them with a pinch of salt

Pascal LeFiscal said:

yes

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Thanks

Pascal LeFiscal said:

but it'll take a long time for stats to converge for f3b so take them with a pinch of salt

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Yeah sure, but for now I'm just tinkering with the basics.


So following on from this, if we know we're against a competent player who will most likely fold or 4bet OOP, and we look at their opening range for say MP and it's 15%, and we also assume he would fold to our BTN 3bet all but the top 3% of hands (i.e. he'll fold 80% to a 3bet in this spot), then we're normally good to go and 3bet right?

Again, lots of assumptions I know (not least that everyone else folds behind lol), but in the spirit of keeping it simple so as to understand the very basic concepts, I'd like to know if I'm way off the mark or not here.

Yes, in a vacuum and assuming villain never adjusts and that he will always 4bet or fold and our equity is always 0% (which it never is) if he raises 15% and only continues with 3% then we need folds 67% (he folds 80%) of the time when making a pot sized re-raise therefore in this spot it's profitable - also notice we rarely make 3bets this large so we actually can get away with fewer folds.

it won't stay at 3% (99+, AKs) for more than a 3bets though - add in 77+, AQ and AJ to anyone reasonably competent when they make an adjustment and open their 4 betting range

and if they aren't reasonably competent then they'll flat 3bets OOP with a wide-ish range after adjusting

pokerman27 said:

Yes, in a vacuum and assuming villain never adjusts and that he will always 4bet or fold and our equity is always 0% (which it never is) if he raises 15% and only continues with 3% then we need folds 67% (he folds 80%) of the time when making a pot sized re-raise therefore in this spot it's profitable - also notice we rarely make 3bets this large so we actually can get away with fewer folds.

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Thanks pokerman... yep, I'm in a vacuum here !

And further if we consider the squeeze play:-

When we lose = -14bb
When we win = +7.5bb

14/(7.5+14) = .65 (or 65%).

So a lot of these preflop plays need to work approximately 65% of the time to BE, and if we have a tight/weak villain who F3B = 85% or something then we should hammer them into the ground PF.

Pascal LeFiscal said:

it won't stay at 3% (99+, AKs) for more than a 3bets though - add in 77+, AQ and AJ to anyone reasonably competent when they make an adjustment and open their 4 betting range

and if they aren't reasonably competent then they'll flat 3bets OOP with a wide-ish range after adjusting

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Agreed, and we need to spot when they do this and readjust ourselves... but that's poker eh!

Again, I just wanted to get some stuff confirmed from a basic approach pov.

Cafeman31 said:

Thanks pokerman... yep, I'm in a vacuum here !

And further if we consider the squeeze play:-

When we lose = -14bb
When we win = +7.5bb

14/(7.5+14) = .65 (or 65%).

So a lot of these preflop plays need to work approximately 65% of the time to BE, and if we have a tight/weak villain who F3B = 85% or something then we should hammer them into the ground PF.

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Short answer, yes.

Long answer, yes but then I 3bet like monkey IP.

Longer answer, yes, although the key here is not just to win (or worse still BE) we want to maximise value so ensure you don't 3 bet someone with a super high fold to 3bet but a high cbet flop when you have a really strong hand as you're losing value.

pokerman27 said:

Longer answer, yes, although the key here is not just to win (or worse still BE) we want to maximise value so ensure you don't 3 bet someone with a super high fold to 3bet but a high cbet flop when you have a really strong hand as you're losing value.

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Yep, I'm flatting AJo etc. EDIT: by really strong hand you mean you flat AA here?

Anyways, how's it going man, last I read you were up to 50nl no?

Cafeman31 said:

Yep, I'm flatting AJo etc.

Anyways, how's it going man, last I read you were up to 50nl no?

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Edit: Yeah, if someone is gonna fold to a 3bet like always but also fire every flop then I'd flat AA.

Yeah, good thanks, haven't been here for a while but still grinding like a demon - a mixture of run bad and bad play (fml) means I'm still at $50NL and doing ok...$100NL by Christmas I hope.

How's your game?

pokerman27 said:

Yeah, good thanks, haven't been here for a while but still grinding like a demon - a mixture of run bad and bad play (fml) means I'm still at $50NL and doing ok...$100NL by Christmas I hope.

How's your game?

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Basically the same story, only down a stake, I'm playing 25nl 6max right now and hope to get up to 50 asap.

Lifter as in weights? I used to do a lot of powerlifting back in the day. I'm as weak as a 10year old girl now though

Cafeman31 said:

Lifter as in weights? I used to do a lot of powerlifting back in the day. I'm as weak as a 10year old girl now though

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Yeah as in weights - poker and lifting...my main (only!) pastimes...

Against people who 4bet/fold it's better to 3b a polarized range right? People (such as most people in 10nl) who call or fold it's better to 3b a merged range?

I like maths threads so any more spots to think about would be good CM. Also what do you think about the use of 4betting light in 10NL? I haven't done the maths but my general line of thinking is 1) regs can threebet quite light if they think you're stealing a lot 2) a 4b in 10NL usually means the nuts and so only a very small range can continue.
I haven't done the maths though to know if it's profitable and also if we should stack off after 4bing or if we can 4bet then fold. Any ideas?

jbbb said:

Against people who 4bet/fold it's better to 3b a polarized range right? People (such as most people in 10nl) who call or fold it's better to 3b a merged range?

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Seems about right to me.

jbbb said:

I haven't done the maths though to know if it's profitable and also if we should stack off after 4bing or if we can 4bet then fold. Any ideas?

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It's about the same when you work it out (using the formula above). Poke in your own specific numbers, but the result will usually mean that if you reckon he's playing back at you with a 3bet and will fold to a 4bet more than say 70% of the time then give it a whirl

jbbb said:

Against people who 4bet/fold it's better to 3b a polarized range right? People (such as most people in 10nl) who call or fold it's better to 3b a merged range?

I like maths threads so any more spots to think about would be good CM. Also what do you think about the use of 4betting light in 10NL? I haven't done the maths but my general line of thinking is 1) regs can threebet quite light if they think you're stealing a lot 2) a 4b in 10NL usually means the nuts and so only a very small range can continue.
I haven't done the maths though to know if it's profitable and also if we should stack off after 4bing or if we can 4bet then fold. Any ideas?

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I think 4 betting light at the lower limits is probably a dangerous game overall. I would need to know someone is capable of 3 betting light and how they react/play post flop before I made any moves. That said the maths of the situation remains the same, just remember you're dealing with narrower ranges overall.

jbbb said:

Against people who 4bet/fold it's better to 3b a polarized range right? People (such as most people in 10nl) who call or fold it's better to 3b a merged range?

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One addition to this. IMO if they are calling 3bets a lot, then I flat OOP with good hands. I will 3bet IP sure, but I don't want to be in an inflated pot OOP with AJ and a calling station staring down at K87.

4 bet folding at 100bb tables doesn't sound good at all

pokerman27 said:

I think 4 betting light at the lower limits is probably a dangerous game overall. I would need to know someone is capable of 3 betting light and how they react/play post flop before I made any moves. That said the maths of the situation remains the same, just remember you're dealing with narrower ranges overall.

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Well I say "three bet light" with a pinch of salt. i.e people are capable of 3bing like QKs AJs AQs but these hands can't really stand a 4b b/c the 4b range of most people in 10NL is just AA,KK,AK and probably QQ.
For example i'm at a table now with a reg who 3b 7% over 500 hands. It's not a big 3b % but if I 4b he will probably have to fold everything but AA-QQ and AK (unless he cottons on) which means hes folding like 75% of the time.

Pascal LeFiscal said:

4 bet folding at 100bb tables doesn't sound good at all

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If they 5b it's probably gonna be AA,KK,QQ,AK so I can 4b to $2.10 and then fold if they jam for another $7.90. I don't think many people flat 4bets, even if they do I have flop equity and can just assume they have AA or KK anyway.

I dunno I was just entertaining the idea.

Idk if this has been mentioned yet, but APPARENTLY on pt3 the ft3b stat includes when the person isnt the original raiser, so that should be looked at cautiously if that is the case

imwatcher said:

Idk if this has been mentioned yet, but APPARENTLY on pt3 the ft3b stat includes when the person isnt the original raiser, so that should be looked at cautiously if that is the case

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This is correct and is a major flaw - will be fixed in PT4. Pretty sure you can download a report that fixes it but not 100%

Flatting OOP with good hands is the proper response to light 3-bets.

Flatting KK+ OOP is probably correct against everyone except people who are willing to stack off light and the tightest 3-bettors.

Cafeman31 said:

Thanks pokerman... yep, I'm in a vacuum here !

And further if we consider the squeeze play:-

When we lose = -14bb
When we win = +7.5bb

14/(7.5+14) = .65 (or 65%).

So a lot of these preflop plays need to work approximately 65% of the time to BE, and if we have a tight/weak villain who F3B = 85% or something then we should hammer them into the ground PF.

Click to expand...

Can you tell me the best book to purchase that covers the math of poker?

jchris67 said:

Can you tell me the best book to purchase that covers the math of poker?

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Not sure about the 'best' book, but this one is quite good: http://www.qtippoker.com/poker-math-that-matters/

Or anything by Sklansky I guess...

As mentioned just be aware that the F3b stat is a) not always converged properly, and b) an average of the stat.

That means there are spots where people are a lot more likely to call/4bet vs a 3bet (often when their range is tighter, ie utg), and spots where they are generally less likely to fight back (for people who open wide OTB for ex, they often have higher F3b%s).