Table 'Lambda Velorum' 6-max Seat #1 is the button
Seat 1: Fish ($470.86 in chips)
Seat 2: UnbeatableReg ($500 in chips)
Seat 3: Fish ($1922.60 in chips)
Seat 4: Villain ($598.85 in chips)
Seat 5: Reg ($617.56 in chips)
Seat 6: Hero ($520 in chips)
UnbeatableReg: posts small blind $2.50
Fish: posts big blind $5
* HOLE CARDS
Dealt to Hero [Tc Kc]
Villain: raises $10 to $15
Reg: folds
Hero: calls $15
Fish: folds
UnbeatableReg: folds
Fish: folds
FLOP [7h Qc Ah]
Villain: bets $25
Hero: calls $25
TURN [7h Qc Ah] [9c]
Villain: bets $65
Hero: calls $65
RIVER * [7h Qc Ah 9c] [As]
Villain: checks
Hero: bets some amount

Sorry for the lack of conversion, the RIO converter doesn't seem to support hiding results any more.

So this is a fairly common river spot that always feels difficult to balance. I feel as though either villain is bluffcatching his Ax to a decently large size, or he's folding all his missed draws to like 1/4 bet or something.

So, in a vacuum when we have value, we'd rather pot it. In a vacuum where he end up with a bluff, we'd rather go 1/4 pot. Lets say 1/2 pot for the sake of this discussion.

Whatever size I choose I feel I'm making some sort of mistake. If we don't go big, then villain might be able to soul read and call some barrelled 9x, 7x or Khi flushdraws. If we go big, we're losing more than we need to VS his CCs that are always CCing anyway.

What size fits all?