If the bet was the last bet (so the guy is betting all in so no more money to win if we call), then we need to win a higher % of the time than our bet is to the pot in order to be profitable.

1) We're 33% chance to hit our draw, and the pot is $10 and we need to call $5. Two times we lose $5 and one time we win $10. Thats break even.

2) We're 33% chance to hit our draw and the pot is $15 and we need to call $5. Two times we lose $5 and one time we win $15. We make $5 every 3 times.

3) We're 33% chance to hit our draw and the pot is $15 and we need to call $10. Two times we lose $10 and one time we win $15. We lose $5 every 3 times.