An over/under, or totals bet, is a wager on whether the combined score of both teams in a game will finish above or below a number set by the sportsbook, with no bearing on which team actually wins.
DraftKings set the Chiefs-Titans total at 52 for the 2020 AFC Championship Game. Kansas City won 35-24, an 11-point margin, but the number that mattered for a totals bet was the combined 59 points, which cleared 52 and cashed the over regardless of how lopsided the game itself was.
A total posted at a flat 46 instead of 46.5 risks a push: if the two teams combine for exactly 46 points, every over and under bet gets refunded. Books add the extra half point specifically so the combined score can never land on the number itself.
A Push occurs when the result of a bet lands exactly on the number set by the sportsbook. It is essentially a "tie" between you and the house. Because there is no winner or loser, the bet is graded as "No Action," and your original stake is refunded in full.
A moneyline is a straight bet on which side wins a game outright, with no point spread involved, priced using American odds that show favorites as a negative number and underdogs as a positive one.
A point spread is a bet on the margin of victory rather than who simply wins, with the favorite required to win by more than the listed number of points and the underdog allowed to lose by less than it, or win outright.