1. The Gap Concept states that you should call a preflop raise with a better hand than you would raise with in the raiser's position.

2. BUT postflop, people always comment that a medium coordinated flop has a high likelihood of hitting the preflop caller's range (meaning medium suited-connectors).

1. and 2. contradict each other. This has bothered me for years.

Could anyone help me with this? Thanks.

A medium co-ordinated flop can still connect with a reasonably strong calling range. e.g 9hQh8d is going to hit an opponents flatting range in a lot of spots.

Plenty of opponents aren't aware of the gap concept or position and simply flat raises due to pot odds or because they like particular hands.

Some opponents are aware of the gap concept but flat raises with scs and raggy Ax anyway.

The Gap Concept doesn't state that.
The gap concept is that you should call with a tighter/stronger range than you'd use for an opening range in the same position.
e.g. You'd typically open AJ in middle position, but if someone opens the pot before you, you shouldn't call with AJ.
To put it another way, you might open 20% of hands in the hijack seat if the action is folded to you, but if someone opens before you, you might only play 10%.

The gap concept is specifically useful when shortstacked and your only good options are shove or fold. You might be in a spot where you'd open jam 25% of hands if you get the chance, but if someone else jams before you there are very few hands that can profitably call. This is the case because the opener can leverage fold equity (he makes money from getting folds), but a caller can only win by making the best hand. You'd usually need your calling range to be about half the size of the jammer's, since even the worst hand you call with has to beat 50% of villain's range.

so inspiring reading arty's posts. Just sayin. Passion for the game right there

Passion for pedantry imo.

What you should do and what people do are seldom the same thing.

Precise language is vital in technical discussions though, so nit on dude

Yes Arty, I agree that you're correct about the "range" meaning of the Gap Concept.

But that still doesn't explain the contradiction I mentioned. Say EP raises with AKs, and is called in MP or LP. Flop comes J98r. Every commentator now says this flop hits the CALLER's range very hard (e.g., with QT or 76). But how is this possible given callers are supposed to highly respect an EP raise? How can the caller possibly connect with that flop when facing an EP raise?

The other poster said many players these days totaĺly ignore the Gap Concept, so maybe that's the answer.

The Gap Concept doesn't have a whole lot of utility in the modern game, although it remains the case that you should call with a narrower range than the range you'd open with in the same spot. (FWIW, I don't like how the concept is often formulated as "you need a stronger hand...", when hand strength is relative, not absolute. AJo is a strong hand in an absolute sense, but it's a weak hand in relation to a range like 99+/AQ+).

For clarity, suppose that EP opens with 15% of hands. A caller in LP will call with a range about half as wide as that. i.e. He'll call with about 7-8%*. But the hands he calls with should not necessarily be the "top" half of the range in absolute strength. He should call with the 7-8% that expects to make money vs the opener. It turns out (as I alluded to earlier) that instead of calling with possibly dominated high cards like AJo, he'll have more equity vs the raiser with hands like JTs, 98s, 77. That's why on a board like J98, the caller often has more strong hands than the raiser. The raiser has a lot of AK/AQ (and Ax in general) type hands. The caller has suited connectors and mid pairs that connect well on the boards that the PFR misses.

The above assumes that the open wasn't a shove. When someone shoves, you ignore "post-flop playability" and most of your calling hands will have "high card strength". Your calling range will still, however, be much narrower than the range you'd jam with yourself.

* I don't want to add to your confusion, but calling frequencies should also change according to how many other players are yet to act, and in some cases the calling frequency should be much less than half as often as the opener raises. e.g. If UTG opens 10% in a full ring game, the next player should not be flatting 5% in theory, because of the risk of getting squeezed by someone else. He can probably only play QQ+/AK (2.6%), and should almost always 3-bet, not call. If the action folds around to the button, however, he can call with about 7%, because a squeeze is less likely, and he knows exactly which boards the UTG player will miss. That's why the BTN could flat with hands like 77, 76s and 65s, but would fold AJ/AT. Since UTG has such a strong range (big pairs and big aces), the caller on the button will call with the few hands that have the best chance of "cracking" those big pairs.

Arty, thanks for your last reply ..I totally get it. It's better to call with a hand of lessor "absolute value" than a top hand. Your 2nd paragraph reminds me of what Chris Ferguson mentioned in his first chapter in the old Full Tilt Tournament book: dominated hands have worse equity against a premium hand like AK than, say, suited-connectors.

I'm serious: you should write a book as you answer everyone's questions with great advice (better than most books on the market).

Agreed, feel like 85% of all information I’ve gathered from this site has been from this guy. Thank you man, keep up the great work.

Flat calling a preflop raise both raises the bottom of your range (due to the fact that you will call a narrower range then you would have opened because of the lack of fold equity) as well as caps it (the top end of your range will usually result ina 3bet). This leaves a lot of midstrength, coordinated cards, and middle pocket pairs. A medium coordinated board is going to tend to connect hard with a flatted range.

and that is why we see so many loose players getting on so called rushes, and deemed being so lucky. it isnt that they are lucky it is that they play more of the hands that do well against the tighter players than ones that are so called dominated because they play more hands period. which too may better players make the mistake of getting in the pot with these hands that get them killed.

there is one important facor nobody mentioned here: vaaaast majority of poker players are losing (likely up to 90-95% in lowest stakes due to high rake), which means that is usually correct to assume that an unknown opponent will be playing badly. Therefore, even if a type of board doesnt hit correct calling range, it might be in line with a calling range represented by population.

I think that in position calling ranges are a function of these factors in the order that I consider them:

Raise size

Openers range

My hand

Players behind me

——

Then I make my decision to call or fold if my hand satisfies these qualities:

My hand plays ok vs the opponents range and my range as a whole can handle the possibility of a 3 bet. Then I call.

My hand plays well vs the opponents range but my range cant handle the possibility of a 3 bet. Then I fold.

The former occurs when the players behind are passive. The latter occurs when the players behind are aggressive.