Page "Pot odds" Paragraph 4

The expected value of a call is determined by comparing the pot odds to the odds of drawing a card that wins the pot.

When the odds of drawing a card that wins the pot are numerically higher than the pot odds, the call has a positive expectation ; on average, you win a portion of the pot that is greater than the cost of the call.

Conversely, if the odds of drawing a winning card are numerically lower than the pot odds, the call has a negative expectation, and you can expect to win less money on average than it costs to call the bet.