Beating the closing Line is a rare edge

When evaluating a team's or model's performance, it's essential to look beyond the win-loss record. A more nuanced metric is Closing Line Value, which measures the difference between a team's actual performance and the final betting line. This metric is crucial because it indicates whether a team is truly outperforming expectations or just benefiting from luck.

The numbers show that beating the closing line is a significant achievement. With a CLV of 0.28 points, that's the difference between a coin flip and a 55/45 favorite. Additionally, a CLV percentage of 53.5% means that the team is outperforming the market's expectations more often than not. To put this into perspective, this translates to a 6% advantage over a 50/50 chance, which is substantial in the world of sports betting.

However, it's essential to acknowledge the small and slow nature of this edge. With a sample size of 2056 games over a four-year window, from 2021 to 2024, the results are statistically significant but not overwhelming. This means that the edge is not a guarantee and may not be visible in the short term.

• The edge is small, with a CLV of 0.28 points
• The edge is slow, requiring a large sample size to become apparent
• The edge is not a guarantee, and results may vary in the short term

A small edge can add up over time, but it's not a get-rich-quick scheme

In practical terms, this means that when evaluating a team's or model's performance, it's essential to look at the CLV over a large sample size. A rule of thumb is to require a minimum of 1000 games before making any conclusions about a team's or model's edge. This helps to ensure that the results are statistically significant and not just a result of luck.