And I looked at the C/R range
just look at the amount of Tx we have
And then it mixes in good backdoor hands like 76s 98s (those will be the ones with the suit with the card on board that can barrel the 9 extra turn outs) - and J9s with some added pair outs that seems very straightforward to me
The underpairs especially (22-44) especially might feel counter-intuitive, 5x little less so
But the reason why you see this is that they will
1) struggle to realize equity when the c/c
so folding out other hands and denying them equity has great value for them
2) Still have ev in the C/R+ Check down line where the raiser bet + calls some of his better A high
This was like my first wtf moment with solvers years ago, a very common spot where you'd 3bet and go bet check+jam with a crappy top pair on the turn that's medium-connected because it'll be hard for you to realize your equity as you have to go check/call turn to check/fold on a lot of river cards
So instead you jam, and deny you opponent's equity with his mediocre hands that can both connect or bluff the river, and sometimes get it in good vs rare good draws, pair+draw. That was the day I knew the bluff/value thinking is just dead and you need to think more fluidly in terms of equity and the rest of the tree in the hand.
And the weak pairs here check/raising are a similar concept