What does Backdoor Cover mean in betting?

Backdoor Cover is a situation where a team covers the spread at the very end of the game, even though it spent most of the match on the wrong side of the line.

What does it look like in practice?

For example, a team may be failing to cover +7.5 for most of the game, but in the final seconds it scores a meaningless basket or picks up late “garbage time” points. That does not change the winner of the game, but it suddenly makes the spread bet win. That is exactly the kind of finish called a Backdoor Cover.

The term is used most often in basketball and American football, where late points can easily change the spread result. For a bettor, it is more a description of the ending than a separate strategy. But in betting language, the phrase comes up often because this kind of finish happens regularly and usually saves one side while frustrating the other.