Eff Stacksize 880
Preflop: HJ opr 12, CO call, BU (me) calls (88), SB active Fish 3bets 50 (but low 3bet frequency, so he got a strongish hand almost always), HJ call, CO call, BU call ; Pot 204

Flop: A86rb, SB bets 100, HJ fold, CO raise 250, BU call, SB fold ; Pot 804

Turn: 2, HJ checks, now whats our most winning sizing? Villain is not stupid, he knows i am most likely on a set here and the only hand he might not be folding is 66. He is very capable of bluffing the Flop with hands like 57 or 79. Since 66 doesn't matter we target 57 and 79. What sizing makes us the most money against those hands. If we jam he always folds those.

I did bet 260 on the turn leaving me 320 behind. I think i should have bet just a little bigger like 310 or something.

Now i calculated, his Eq with 97 is 18.18%, i gave him Potodds of 18.6%. So his call is only a very tiny mistake when i deny him implied odds by folding on a T or 5 River for example.

What sizing would you choose?