Maths question

Originally Posted by MadMojoMonkey

Why does he force the case that OOP never flats a 3-bet? Is this GTO? Did I miss that part of the explanation?

Never being allowed to call 3bets OOP, and never being allowed to call 4bets at all is to massively simplify the calculations in a way that sort of makes sense (since calling 3bets OOP so often puts us in horrible spots, and since 4bets are often big enough that they are often effectively a pot commitment point anyway). The main point of the series is to teach how to perform these kinds of calculations so that you can go off on your own and construct decently balanced unexploitable ranges in lots of spots. An actual (non-approximate) GTO strategy would almost certainly include calling some 3bets OOP and calling some 4bets, and this is something that people seem to be doing more of these days as a result.

Originally Posted by Pelion

Never being allowed to call 3bets OOP, and never being allowed to call 4bets at all is to massively simplify the calculations in a way that sort of makes sense (since calling 3bets OOP so often puts us in horrible spots, and since 4bets are often big enough that they are often effectively a pot commitment point anyway). The main point of the series is to teach how to perform these kinds of calculations so that you can go off on your own and construct decently balanced unexploitable ranges in lots of spots. An actual (non-approximate) GTO strategy would almost certainly include calling some 3bets OOP and calling some 4bets, and this is something that people seem to be doing more of these days as a result.

I don't think it's all that realistic to assume no calling 3b oop, but I think it's reasonable to assume no flatting 4b at least.