ISF Theorem

I think this is ISF theory. It just went a bit differently than I expected. Over about 80 hand villain was ~74/33/3.3. I was 23/15/1.5, and hadn't been getting out of line with 3bets or post flop raises on any street.

My range to open/call UTG and c/r that flop is so far ahead of so many of the hands he's 3betting preflop, and cbetting when checked to, that it becomes a great spot to c/r bluff, right?

That was my line of thinking at the time during the hand (before I had read your post for the first time in like 2 years).

PokerStars No-Limit Hold'em, $0.10 BB (5 handed) Poker-Stars Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Button ($33.70)
SB ($10)
BB ($10.20)
Hero ($18.65)
MP ($9.25)

Preflop: Hero is UTG with A, Q.
Hero raises to $0.5, 1 fold, Button raises to $2, 2 folds, Hero calls $1.50.

Flop: ($4.15) 7, 3, 8 (2 players)
Hero checks, Button bets $2, Hero raises to $6.5, Button raises to $11, Hero raises to $16.65, Button calls $5.65.

Turn: ($37.45) A (2 players)

River: ($37.45) T (2 players)

Final Pot: $37.45

Also, quick question ISF:

Are we more concerned with what our range looks like before or after the prospective action we're thinking about making.

Obviously there's a balance that needs to exist because we want the hands in our range before our prospective action to skew towards hands that will be towards the top of our range after our action (As the more bluffs/semi-bluffs we are likely to have in our range the less fold equity we have). But, in general Is the range we're representing by our action more or less important than the range we were representing leading up to our action?

Overflow, see flaw 1 of ISF's theorem in regard to your HH & playing @ 10NL.

The range you are representing is a combination of both your previous actions & the action are making on this street. If the two dont add up, your range will look like a bad bluff most likely.

Erpel: Seems like a bad play unless you bet much more and that may not be good.

Overflow: Also pretty bad. Note with huge donks most of them dont put you on a range of hands, so they dont really care.

"Is the range we're representing by our action more or less important than the range we were representing leading up to our action?"

I think the answer to this question if I understand it correctly... is both are important (they really seem like the same thing).

If we are in a spot where we could only represent the nuts on the flop we will only be able to represent the nuts on the turn (Extreme example of why they seem like the same thing)

Let's say I open from the cut off for 3.5x in any 6max game under 50NL. I probably raise about 27% of my hands from the cut off which looks something like:

22+,A2s+,K9s+,Q9s+,J9s+,T8s+,96s+,86s+,75s+,65s,A7 o+,K9o+,QTo+,J9o+

Let's assume the BB is your average 45-55/5/1.0 fish, who loves to defend his big blind, we'll say38%:

AcAd,KcKh,QcQs,QcQh,JJ-22,AcKc,AdKd,AcQc,AdQd,AJs-A2s,K3s+,Q8s+,J8s+,T8s+,97s+,86s+,76s,65s,54s, half the AKo combos,AQo-A2o,K8o+,Q9o+,J9o+,T9o


If the board is:

Ad 6s 9h

If they check, their range changes because there are certain hands in that range this player wouldn't check. Or wouldn't check often enough for it to be practical to consider.

If they bet their range changes, a large number of these hands will not bet the flop if they miss OOP. If they bet it narrows their range, because they won't donk 100% of their range when defending on this board (although whether or not they should is debatable).

I guess it comes down to the whole "it depends", and poker is very situational. But I'd like to believe (and at some point I will run simulations to back this up) that there are more transition states in hold 'em that result in ranges being altered than result in them staying the same (excluding transitions which result in the completion of the hand).

I guess the general rule is that the aggressiveness or passivity of the opposing player will dictate whether his range is more greatly affected by betting, checking, calling, or check calling.

overflow, i dont really get what your saying, but if its simply that if someone bets it alters (weakens or strengthens) their checking range then yeah that's true.

Basically the general idea of what I was saying is that we can use villain's TAF as a pseudo-range indicator.

For example, if an opponent with an aggression factor of 3.0+ checks the flop with the lead, it gives us a lot more information for reducing his range because it's the action he takes least frequently.

The more frequently an opponent makes a certain action, the less information it gives us to reduce his likely range, because he's taking that action with a larger percentage of his range.

I think a better example is the converse situation.

You have a 15/10/0.7-1.0 nit, who almost never bets the flop without a strong draw, or at least a pair with a decent kicker.
If he bets the flop you should probably only continue with well disguised draws, and TPTK+. Why? Because this nit only bets for value. His range constricts significantly when he bets the flop, because only a small percentage of his range could've connected.

It's kind of an extension of your theorum. You should be more likely to bluff if your range is ahead of their range, but you should also be more likely to bluff if villain (in a HU pot) takes a line that goes against their natural tendencies.

I mean, can't you almost raise a nondescript flop almost every time when a 3.0+ aggro monkey bets, or bet the flop when a <= 1.0 nit checks, just because their range is air so much?

Kinda just wanted to take the double post but after I played this I figured it had to be ISF theorom. amirite?

$0.5/$1 No Limit Holdem
5 players
Converted at weaktight.com

Stacks:
UTG ($160.00)
CO ($54.20)
Hero ($156.45)
SB ($98.75)
BB ($211.85)
[UTG posted $1.5]

Pre-flop: ($3, 5 players) Hero is BTN
UTG checks, 1 fold, Hero raises to $4.75, 1 fold, BB calls $3.75, UTG folds

Flop: ($11.50, 2 players)
BB checks, Hero bets $9, BB raises to $36, Hero raises to $109.50, BB folds

I was thinking ISFT at the time, and I wanted to try that half-pot, third-pot, shove river 3bet pot line. Worked well here. Not sure if villain folded QT, or like a MPP but if he folded a jack, it was a great line to take.

PokerStars No-Limit Hold'em, $0.10 BB (5 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

Hero (SB) ($11.20)
BB ($19.20)
UTG ($10.45)
MP ($8.65)
Button ($9.45)

Preflop: Hero is SB with A Q
2 folds, Button raises to $0.30, Hero raises to $1.40, 1 fold, Button calls $1.10

Flop: ($2.90) J 4 9 (2 players)
Hero bets $1.60, Button calls $1.60

Turn: ($6.10) 6 (2 players)
Hero bets $2.00, Button calls $2.00

River: ($10.10) 4 (2 players)
Hero bets $6.20 (All-In), 1 fold

Total pot: $10.10 | Rake: $0.45

Originally Posted by Squeaky_Midget1

Kinda just wanted to take the double post but after I played this I figured it had to be ISF theorom. amirite?

$0.5/$1 No Limit Holdem
5 players
Converted at weaktight.com

Stacks:
UTG ($160.00)
CO ($54.20)
Hero ($156.45)
SB ($98.75)
BB ($211.85)
[UTG posted $1.5]

Pre-flop: ($3, 5 players) Hero is BTN
UTG checks, 1 fold, Hero raises to $4.75, 1 fold, BB calls $3.75, UTG folds

Flop: ($11.50, 2 players)
BB checks, Hero bets $9, BB raises to $36, Hero raises to $109.50, BB folds

This is the only example of isf theorem on this page.

I think you're 3-bet can be a lot smaller though and accomplish the same thing.

great stuff ISF.

How come this is not sticky'd? I found it randomly and would have loved to have read it earlier b/c I am new to cash games.

This was posted in the BC, and i was wondering if this is correct application of ISF theorem:

No-Limit Hold'em, $0.25 BB (6 handed) - Hold'em Manager Converter Tool from FlopTurnRiver.com

Button ($29.80)
SB ($26.80)
BB ($25.40)
UTG ($35.75)
Hero (MP) ($26.10)
CO ($8.20)

Preflop: Hero is MP with XxYy
1 fold, Hero bets $0.75, 3 folds, BB calls $0.50

Flop: ($1.60) K, 6, 3 (2 players)
BB checks, Hero bets $1.25, BB calls $1.25

Turn: ($4.10) 3 (2 players)
BB checks, Hero bets $2.25

Of course, this assumes that both players are capable of thinking through ranges and that BB plays solid preflop poker:

BB is likely to 3b KK, AA and AK pre, and he isn't usually going to set mine 33 (prob 3b or fold), so 66 seems like the only viable possiblity in BB's A range. so the best hand BB will usually have is like KQ, and he may not even call that OOP to an MP PFR. Hero has all the aforementioned hands in his range and not all that many draws and not all that many bluffs (because people don't often barrel turn blanks on dry boards at 25nl), so hero has a perceived strong range.

how'd i do?

(edited, cause i suck at life with copying and pasting HH's)

against MP I'd setmine 33, against CO I'd 3b or fold
also I call KQ anyway because there are worse made hands in MP's range and he could be barreling a picked up spade draw, 45, air

but against people who take one off with 77-JJ here and fold to a turn barrel I'd barrel
so it's really a product of flop range and turn range
I try to fold enough hands on the flop and call with marginal hands on the turn so I'm not as easily exploitable in this situation

so I might call two streets with JJ here; but fold to the bet flop, check back turn, bet river line
I am also going to check/call 66 on the flop and check/call turn to protect my c/c two streets line against an aggressive opponent
but I would say a lot of people are going to peel too light on the flop and fold too much on the turn

Originally Posted by surviva316

This was posted in the BC, and i was wondering if this is correct application of ISF theorem:

No-Limit Hold'em, $0.25 BB (6 handed) - Hold'em Manager Converter Tool from FlopTurnRiver.com

Button ($29.80)
SB ($26.80)
BB ($25.40)
UTG ($35.75)
Hero (MP) ($26.10)
CO ($8.20)

Preflop: Hero is MP with XxYy
1 fold, Hero bets $0.75, 3 folds, BB calls $0.50

Flop: ($1.60) K, 6, 3 (2 players)
BB checks, Hero bets $1.25, BB calls $1.25

Turn: ($4.10) 3 (2 players)
BB checks, Hero bets $2.25

Of course, this assumes that both players are capable of thinking through ranges and that BB plays solid preflop poker:

BB is likely to 3b KK, AA and AK pre, and he isn't usually going to set mine 33 (prob 3b or fold), so 66 seems like the only viable possiblity in BB's A range. so the best hand BB will usually have is like KQ, and he may not even call that OOP to an MP PFR. Hero has all the aforementioned hands in his range and not all that many draws and not all that many bluffs (because people don't often barrel turn blanks on dry boards at 25nl), so hero has a perceived strong range.

how'd i do?

(edited, cause i suck at life with copying and pasting HH's)

Seems like good reasoning.

Although, i think other factors may weigh out isf theorem here. I'd be inclined not to two barrel in this situation with air.

well it's kind of like the difference between your original formulation of the ISF theorem and your revision on it

your original formulation would say "FUCK! we have KK, AA, AK in our range and he doesn't, we have more nut hands! BARREL!"
but in your revised version it's more like "by calling this flop OOP villain basically defined his hand as a Kx combination or TT-JJ so the frequency of him folding the turn is not going to be high, and while we're more likely to hit the flop, our range on the flop is wider than his range to continue past the flop"

so like it's not about who has the nuts more often, it's about whose hand range has a higher equity including air

My understanding of ISF theorem:

All hands that are better than 50% of your opponent's range can add some value to your betting range. The more of your opponent's range the hand beats, the more value it adds. For every set amount of "value" in your value betting range, you can add a certain number of bluffs. If your value range is strong enough, it can allow you to bet your whole range. Hands that beat a medium % of your opponent's range add little or no value to your value-betting range but they do add value to your checking range. If your range contains a lot of these kinds of hands then it can be better to use the stronger portion of your value range to bolster this checking range.

Interesting to see that no one seems to be submitting examples of when they checked good hands in a weak range because of ISF theorem. They're all about betting bad or medium hands in a strong range.