How Much Must You Play With a Guy Before Saying He Never Bluffs?

[PokrLikeItsProse]

Let's say you play the same limit at your local casino on a regular basis and you get to know a lot of the regulars. It's your normal loose, passive, no fold game on most days. One player will check and call the flop and turn OOP and bet the river when the third card of the suit comes and he seems to always turn over the flush.

How often can you play with this guy where he always has the flush in this spot before you can start folding on the river, even in big pots, because he never bluffs in this particular situation? Let's say that you've also seen him check straights and sets because he usually fears the flush.

Less specifically, how much do need to play with someone to know he never bluffs (some people don't) in certain situations, so that you can make what look like big laydowns because you know the player, even if the pot looks big?

[Harv72b]

I don't know that it's possible to ever say that a guy "never" bluffs--even if you've seen him show down nothing but the nuts the last 100 times he led the river, there's always the possibility that on the 101st time he decided you'd just fold & bet a busted draw.

So it's all about how often you think he'll be bluffing vs. pot size. If we're talking about a multiway pot that sits at 20 BBs, it's 1 bet to you closing the action on the river, and you're holding top set after the flopped flush draw just hit, you make the call because the pot is friggin huge and he only has to be betting second set or two pair or have misread his hand 1 in 20 times to make it correct. On the other hand, if you're holding top pair on that same board & Mr. Passive leads into you in a 4 BB pot, you can pretty safely fold.