How do I determine which team is favored to win (Chalk) and the team most likely to lose (Underdog)? The + and – symbols are used to show the chalk and underdog. The negative symbol indicates the chalk and the + symbol indicate the underdog. Related articles How do I access Live Chat? Why am I not able to play on my PC? How do I sign up for a FireKeepers iCasino & Sportsbook account? How do I reset my password?