Closing line value: the best sign you're beating the market

The closing line is the last line before tip-off. By then every bit of news is in: injuries, lineups, the betting of the sharpest players. It is the most accurate line a bookmaker ever offers.

Closing line value (CLV) is how your line compares with it. If you bet over 24.5 and the prop closed at 25.5, you beat the close by a full point. If it closed at 23.5, the market went against you.

Why it predicts results

Your win rate swings with luck for hundreds of bets. A good bettor can lose for a month; a bad one can win. CLV cuts through that. If your lines keep beating the close, you are consistently betting before the market moves your way, which is what an edge looks like.

Bettors who beat the close over time tend to win over time. Bettors who don't, rarely do, however good last month was.

How to read it

• For an over: positive CLV when the line closes higher than yours.
• For an under: positive CLV when the line closes lower than yours.
• Same line, different price: a better price than the close counts too.

One bet tells you nothing. Look at the average over 30, 50, 100 bets, and at the share of bets that beat the close.

How to get more of it

• Bet early when you have a real reason, before the news is priced in.
• React to injury news fast. When a starter is ruled out, his teammates' lines move within minutes.
• Shop lines. The best line available is often already a step ahead of the close.

On NBA House

The bankroll tracker records the closing line of every player prop on the board at tip-off: the line most bookmakers had at their last read, or the board's own line when none was read. For each prop bet logged before tip-off, and for the whole bankroll, it shows how your line compared with it.