Chalk

What is Chalk?

Chalk is slang for the favorite in a betting matchup. When someone says they're "betting the chalk," they mean they're taking the favored side. A "chalk bettor" is someone who consistently bets favorites.

Origin

The term comes from the days when odds were written on chalkboards. Favorites were bet more heavily, so their odds were erased and rewritten more often, leaving chalk dust — hence "chalk."

Chalk vs. Value

Betting chalk isn't inherently good or bad. What matters is whether the favorite offers value — meaning the true probability of winning is higher than the implied probability of the odds.

Example

• Chiefs at -200 (implied probability: 66.7%)
• If you believe the Chiefs have a 75% chance of winning, there's value in the chalk
• If you believe they have a 60% chance, the chalk is overpriced

Public Bias Toward Chalk

Recreational bettors tend to bet favorites disproportionately, which can inflate chalk lines and create value on underdogs.