Closing line value explained

The closing odds (the "closing line") are the last odds before kick-off. By then, line-ups, injury news, models and the money of many bettors have shaped the price. That is why they are considered the most accurate available estimate of the probability, especially in the major leagues.

Closing line value compares your odds with these closing odds.

The calculation

CLV = your odds / closing odds − 1

It becomes more precise if you first strip the margin out of the closing odds, i.e. use the fair closing odds.

Why CLV says more than profits

Whether a single bet wins is largely down to chance. Even after 200 bets, a bad system can be in profit and a good one in the red. CLV fluctuates far less: after just a few dozen bets it shows whether you are systematically getting better prices than the market. Studies and the experience of professional bettors show that those who achieve a positive CLV over time are, as a rule, also in profit in the long run.

What a negative CLV means

If your CLV is negative over many bets, you are on average betting at prices the market subsequently judges to be too low. Then even good reasoning is not enough: the information you are betting on is already known or wrongly weighted. Rather than more bets, the only thing that helps is changing your approach – different markets, betting earlier or being stricter in your selection.

Limits

In small leagues and niche markets, the closing odds are less reliable because little money is traded. And if you always bet just before kick-off, your CLV will naturally be close to zero minus the margin.