Closing line value (CLV)
How much better the price you took was than the market's final price before the event — the standard measure of a bettor's edge.
Arbitrageurs do not need CLV: the profit is locked in at entry. But CLV explains why arbs are short-lived — the closing line is where all books converge, and a price that disagrees with it is corrected quickly.
Related terms: Sharp book vs soft book · Steam