However, suppose Bob knew (with 100% certainty) that Carol held 8♦ 7♦. In this case, it would be correct to "raise". Even though Carol would still be getting the correct pot odds to call, the best decision for Bob is to raise. Therefore, by folding (or even calling), Bob has played his hand differently from the way he would have played it if he could see his opponent's cards, and so by the fundamental theorem of poker, his opponent has gained. Bob has made a "mistake", in the sense that he has played differently from the way he would have played if he knew Carol held 8♦ 7♦, even though this "mistake" is almost certainly the best decision given the incomplete information available to him.