What is a lock in sports betting?
The short answer
A bet someone considers guaranteed. (Hint: no bet is a lock!)
Betting slang explained
Knowing the language is step one — knowing the true price is the edge. The Cold Line’s signal desk tracks the no-vig fair number and the closing-line value behind terms like this, before the market moves.
In plain English
When someone's super confident. "This is a lock!" Still can lose though.
What to remember about Lock
The definition
A bet someone considers guaranteed. (Hint: no bet is a lock!)
In plain English
When someone's super confident. "This is a lock!" Still can lose though.
Example in context
"He called it a lock and it lost by 20."
Keep learning
Explore the next question before you place a bet.
Put the concept to work
Explore Lock with a concrete research workflow. Build your own number, compare sportsbook prices with a sharp reference, or use Audits to review timestamped book moves beside play-by-play.
Browse the full A–Z betting glossary or read the complete betting guide. The Cold Line also publishes a free year-round sports calendar and an odds board (Free account: delayed odds).