Bookmakers and popular opinion strongly favor one side, usually a team or player, to defeat its opponent in a chalk matchup. The chalk matchup selects the group called "chalk." Bookmakers typically offer shorter odds on underdog bets when everyone expects a certain outcome in a sporting event. Chalk matchups are popular in betting discussions and strategies because of their lopsided probability of winning. Bettors weigh the risk-reward balance and potential returns when betting on the favorite.