unders

Unders is a term used in sports betting referring to wagers that the total combined score, runs, or goals of a game will be under a published line. The line is part of the over/under market, a common bet across many sports where bookmakers set a projected total and bettors choose under or over. The plural “the unders” can refer to such bets collectively or to multiple instances of this bet.

How it works: If the line is 215.5 for an NBA game, a bettor who takes the under wins if the final combined score is 215 or less; if the final total is 216 or more, the bet loses. The under line often uses halves to avoid ties; lines like 215.5 guarantee a win or loss rather than a push. If the final total equals the line (in a whole-number line with no halves), many sportsbooks treat it as a push and return the stake.

Line setting and strategy: The unders is influenced by team pace, defense, injuries, weather (especially in football), and game tempo. Bettors may consider pace metrics, defensive efficiency, recent form, and variance due to randomness. Some bettors track public betting trends and line movements to identify value, while others rely on statistical models.

Scope: The principle applies across sports—American football, basketball, soccer, baseball—though the frequency and typical margins of under bets vary by sport. The term is widely used in the U.S. and other betting markets.

See also: Over/under, betting markets, push.