When defending in position Matt concludes that your opponent shouldn't be able to profitably bet any two cards when out of position, on most boards. I disagree with this conclusion and most of his explanations.
The first reason he gives is that "our in position calling range is designed to play effectively against our opponent’s preflop raising range."(pg 99) I don't see how this point requires that we not let our opponent bet any two cards profitably. Our out of position blind range is designed to play effectively against our opponents preflop raising range, but the same argument doesn't apply. In fact, all ranges are always designed to play perfectively effectively from a GTO standpoint. But Matt doesn't explain why letting our opponent bet any two cards profitably is allowing him to exploit us.
Matt later implies that if our opponent can make a profitable bet with any two cards than he'll always bet and never check -- which is certainly wrong. But just because your out of position opponent can bet any two cards profitably doesn't mean that betting is higher EV than checking. In fact, Matt makes this exact point when analyzing the in position player. So we can't fold too much that it's higher EV for our opponent to bet all his hands, and even technically bet any hands which should in theory be higher EV as a check.
Quote:
While even a hand as weak as deuces has a positive expected value when it’s checked out of position on a flop of the Jh 9h 5c the expected value of the check should be small and close to zero. If we could profitably bet deuces out of position on this board texture, then even a bet which is only slightly profitable would bebetter than checking. However, most players learn from trial and error that betting a weak hand when out of position has a negative expected value on most board textures even if it cannot be proven directly.
(pg 192)
I don't understand this argument. He says two contradictory things... checking is slightly +EV, betting is slightly +EV therefor betting is higher EV than checking. As long as the in position player has a checking range, than 22 is going to be +EV as a check. And so as long as it's LESS EV as a bet, than there will be no incentive for the oop player to be betting his entire range, including 22 in this situation. He goes on to argue that most people learn that betting 22 is -EV in this situation which makes no sense either because people aren't playing anywhere close to GTO correct, so what they learn in this situation has little bearing on the question. We know that if it's higher EV for our opponent to bet his entire range than we're doing something wrong, but it doesn't tell us exactly how wide we're supposed to defend.
Staying with the previous example, our goal is not to make the oop player's worse hand indifferent between betting and checking. Instead there will be some "stronger" hand that will be indifferent between betting and checking OR a hand very close to the weakest bluff. In other words, it might make sense for the worse hand in our opponents range to be -EV as a bet even if checking is +EV -- as long as he's indifferent between betting and checking with the right hands. Matt describes this equilibrium that forms, "So the conclusion is that defending anywhere between 60 to70 percent of the time on most boards seems like a reasonable guess. This should stop our opponent from profitably betting anytwo cards on the flop. It also allows for enough folding that wegive our opponent an incentive to bluff the hands which are theoretically correct bluffs, yet does not result in us folding so much that he can recklessly bluff any two cards. Likewise we are not defending so aggressively that we give too much value to our opponent’s strong hands." The more we defend the thinner our opponent can value bet, and the higher equity his bluffs will have. So we want to, in general, defend as little as possible without folding hands which would be +EV as a call.
It's hard to know which bluffing hand of our opponents that we are supposed to make indifferent between betting and checking -- or if not indifferent at least know where which hands should go. But let's look at the math a little more and Matt's explanation when to defend more. When our opponent makes a 75% pot size bet, he needs us to fold ~57% of the time to make an immediate profit, and Matt suggests we should be "defending anywhere between 60 to70 percent of the time on most boards seems like a reasonable guess." (pg 103) We are defending with up to 22% more hands than what the Villain needs to make an immediate profit -- this is ALOT more hands. Another way of thinking about it is that if we defend say 68% on the flop, 60% on the turn, and 57% on the river when our opponent makes 3/4 pot size bets, than if he had a hand with 0% equity, it would be ~ -2bb EV bet. Now of course our opponent will have some equity when he's bluffing, but this is quite a bit of EV to make up. "Usually, the board textures where our opponent’s bluffs can likely outdraw us on the turn (such as the Th 8h 7c flop mentioned earlier) are the same ones where being in position is quite valuable. In addition, on these type of flops, we should have many hands which can improve on the turn. Therefore, good strategy implies to defend a wider range on these types of board textures. " Yet at the same time, these are the same boards that our opponents bluffs have equity when they check. In other words, if we defend so much, I'm fairly confident that his weaker hands will be -EV as a bet, but they'll be slightly +EV as a bet, so I don't know why he suggests we should defend so much.
Matt does say in the book that it can make sense to defend more on an early street and less on a latter, but on most drawy boards I don't think he's going to think that on average we should be defending less than 57% of the time on the turn.
My guess is that Matt's defending much wider than GTO correct in quite a few places, and that its important to remember that an opponent will only bet if it's higher EV than checking, not if it's simply profitable.