Chalk

Chalk is a widely used slang term in sports betting that refers to the favorite in a given matchup or event. When someone says they are “betting the chalk,” it means they are wagering on the side that the sportsbook and the market expect to win. The term can describe a team, player, or outcome that carries a negative moneyline (in American odds), a smaller point spread number as the favored side, or simply the selection most bettors and analysts believe is most likely to prevail. A “chalky” card refers to a set of results where most of the favorites won as expected.

The origin of the term dates back to a time when bookmakers wrote odds on chalkboards. The favorites, being bet most frequently, had their odds erased and rewritten so often that their section of the board was always freshly marked with chalk. Over time, “chalk” became shorthand for the favored side. Today, the term is used casually across all sports and betting formats. Heavy chalk refers to a substantial favorite — for instance, a team listed at -300 or higher on the moneyline. In tournament settings such as March Madness brackets, a chalk bracket is one that selects the higher-seeded team in every game.

Example

In an upcoming NFL game, the Kansas City Chiefs are listed at -200 on the moneyline against the Las Vegas Raiders at +170. The Chiefs are the chalk in this matchup. A bettor who places $200 on the Chiefs moneyline would profit $100 if Kansas City wins. A friend who describes their betting card as “all chalk this week” means they have backed the favorite in every game they wagered on.

In a March Madness first-round game, the No. 1 seed is -1400 against the No. 16 seed. This is extreme chalk — the market considers an upset to be very unlikely.

Key Points

• Chalk wins often but pays less: Favorites win more frequently than underdogs by definition, but the lower payout means a bettor must win at a high rate just to break even. Betting chalk is not inherently profitable or unprofitable — it depends on whether the price is accurate.
• Public tends to lean toward chalk: Recreational bettors disproportionately bet on favorites, especially well-known teams. This tendency can sometimes push the chalk price past its fair value, creating potential value on the underdog side.
• Heavy chalk carries hidden risk: Wagering on a large favorite such as -400 requires risking $400 to win $100. A single upset can erase the profits from several winning bets, making bankroll management critical for chalk bettors.
• Chalk is relative, not absolute: A team can be chalk in one market and an underdog in another. For example, a team might be a 2-point favorite on the spread (chalk) while listed as an underdog on a first-half line, depending on the specific market.