Can someone point me in the direction of some resources on theoretically sound IP and OOP bet sizing on turns where there are two cards from each of two suits (e.g., Th8h9c2c)? I vaguely remember hearing somewhere that, counterintuitively, a small bet sizing is indicated most of the time on these sorts of boards, but I could be misremembering that. I don't have access to a solver so any source that discusses bet sizing in this situation (based on the various possible PF and F trees), or anyone that could should some light would be much appreciated. First post on 2+2 so sorry in advance for any faux pas.

Don’t know of any resources specifically on this topic, but I have noticed that we do size down a touch in these situations.

Eg when we’re double barreling in IP SRP, overbet size is usually preferred on blank turns. This is still true when the turn is double twotone, but you’ll often notice that the overbet size is slightly smaller.

I think this is happening because of the numerous pair+fd in the caller’s range. In general, big overbets don’t work as well when you’re up against lots of high equity hands and draws. All we do is isolate ourselves against these hands, and allow villain to fold most of his weak bluffcatchers. By sizing down a touch, we force villain to call with more weak bluffcatchers, effectively reducing the proportion of high equity holdings (such as combodraws) in his continuing range.

I thought we were supposed to jam double flush draw turns with our sets, straights and 2 pair?

My biggest concern is most people don't bluff busted flush draws and I won't get any value from their busted flush draws with my good hands.

I could only run it with two bet sizes 33% and 75% because my laptop is booty. But it wants an OOP player with a range advantage to bet 75%, and the IP player wants to checkback if checked to, but if they do fire its the smaller sizing for 33%

Not necessarily, it depends on what the SPR is, as well as the proportion of better hands in villain's range.

Eg if SPR is high and villain has a significant proportion of sets and straights, then it wouldn't really make sense to jam 2 pair on the turn. Yes you deny some equity against draws, but it's not enough to compensate for the value you lose against weaker bluffcatchers.

On the other hand, if SPR is low and villain doesn't have many hands that beat you, then jamming is perfectly fine, since villain still has to call with many weak bluffcatchers (otherwise your bluffs become too profitable).

You can watch this for a more visual explanation of why we sometimes size down when the board is wet: