Licentia;206301 wrote
Why in the world would I want to call when I only have a 25% chance of winning the hand and I am betting 33.3% of the Pot size? That sounds like a negative EV to me over the long term, at least compared to my method.
Sounds like you're confusing odds with probability. A 25% probability of winning is equivalent to 3:1 odds against winning. That means if you have a 25% probability to hit your outs and are getting 3:1 pot odds, you're net 0 EV if you call. If you're getting slightly better pot odds (or have a slightly better probability of winning, perhaps by factoring in the probability that your opponent could be bluffing and you're already ahead, etc.), then you have correct pot odds to call.
In short, you should either convert all the numbers (from pot and chance to win) to either odds or probability - whichever you feel most comfortable with.
Relating probability to odds against (odds:1):
probability = 100%/(odds + 1)
odds = 100%/probability - 1
Personally, I find it easiest to figure out my probability (from the rule of 2.1% per out on the turn; 2.2% per out on the river), then convert that to odds (1/probability - 1) and compare to the odds I'm getting from the pot (which I find easier). For example, say I've got 6 outs on the river. I figure that's almost 20% to win. 100%/20% - 1 = 5 - 1 = 4, so I need at least 4:1 pot odds (maybe a little less if there's a chance I could already be ahead, or might have a few extra outs that I wasn't factoring in, like an over-card that might pair to win). Then it's just a matter of counting the pot, including any uncalled bets, and dividing that by the amount I still have to call (or intend to bet, as the case may be).