.I'm glad this topic came up. I have learned some things already, but I wanted to bring up a question I looked at a little while back and that is the conservatism of the pot odds calculation. I'll use the 18% odds of hitting a flush on the turn for my example.

Pot size: $100, including bet into you.

Obviously we all know pot odds say the largest raise you can call in this situation is $18, which means the pot was $82 before the flop.

Expected value says a much larger call can be made.

To break even, .18 times the pot must be greater than .82 times the call, so

.18p>.82c, so
.18/.82p>c and
~.22p>c

Which means you are breaking even calling 22% of the pot, not 18%. With more outs, the disparity increases as x/(x-1) approaches 1 as x approaches 1. For example, with an open-ended straight flush draw, 15/47 (pot odds)=32% but 32%/58%=47%.

I guess the conservative philosophy works though and artificially accounts for the expected number of cards that complete your draw that are in the folded hands.