Betting Trends Are Mostly Noise (With Three Important Exceptions)

Every sports betting website has a trends section. "Team X is 14-4 against the spread as a road underdog since 2019." This sounds meaningful. It's usually not.

Here's the problem with most trends: they're backward-looking patterns with no predictive power. Past results don't cause future outcomes. The fact that the Cowboys covered in November 2021 has no bearing on whether they'll cover in November 2025. The roster is different. The coaches might be different. The context is entirely different.

Most trend statistics are also subject to sample size issues and data mining. If you look at enough subsets of data, you'll find patterns that look significant but are actually random noise.

That said, not all trends are worthless. Here are three that I've found have genuine predictive value:

1. Team rest and scheduling patterns

This isn't really a "trend"—it's a structural advantage. Teams playing on extra rest consistently outperform teams on short rest. Teams playing their third road game in a row consistently underperform. These aren't coincidences; they reflect real physical and mental factors.

I specifically track games where there's a significant rest differential and the line doesn't fully account for it.

2. Revenge game motivation

Teams playing against a former coach or star player perform differently. This is psychology, not statistics—there's extra motivation, extra preparation, and often extra emotion. The data backs this up: "revenge games" have a measurable impact on outcomes.

The key is identifying genuine revenge situations versus manufactured narratives. A player facing his former team matters. A player facing a team that didn't sign him as a free agent five years ago doesn't.

3. Season-long performance versus expectation

If a team is significantly outperforming their point differential (winning close games at an unsustainable rate), regression is coming. If they're underperforming their point differential, they're probably better than their record suggests.

This isn't a trend in the traditional sense—it's a correction to the market's tendency to weight recent records too heavily.

The rule I follow: I ignore any trend that doesn't have a clear causal explanation. "The Bills are 7-2 ATS as favorites of 6+ points at home"—okay, but why? If there's no reason beyond "it happened before," I ignore it.

Trends can be useful for generating hypotheses, but they're not evidence. Do the work to understand whether the pattern has predictive power or is just noise.