Player Props

Player props are the fastest-growing part of the betting market and the most misunderstood. They are simultaneously the softest numbers on the board and among the hardest to profit from.

Why the numbers are soft

A sportsbook prices maybe a dozen markets on the game itself. It prices hundreds of player props on that same game — every quarterback, receiver and running back, across several statistical categories, plus alternates.

Nobody can do that with the care they apply to a spread. Prop numbers come largely from projection models with far less market feedback correcting them, because the money flowing through any individual prop is tiny compared to the main line.

The result is genuine, findable mispricing, particularly around usage changes the model hasn't caught — an injury elsewhere on the depth chart, a scheme change, a player returning to a different role.

Why that is harder to exploit than it sounds

Two things eat the edge.

The hold is roughly double. Where a main total holds 4–5%, props commonly hold 6–10%. A prop priced −125 on both sides requires a 55.6% breakeven win rate versus 52.4% on a standard line — a bar more than three points higher, on a market that is inherently noisier to predict.

The limits are tiny. Finding a 6% edge is worth much less when the book will take $250 on it. And betting props aggressively is one of the fastest routes to having your account restricted, because it is exactly the behaviour books watch for.

What actually drives a prop

Opportunity before efficiency. A receiver's yardage is targets multiplied by yards per target, and targets are far more predictable than efficiency. Most sustainable prop edges come from correctly anticipating volume, not performance.

Game script. A team expected to trail throws more. A team expected to lead runs more. The spread is therefore an input to every rushing and receiving prop on the board.

Distribution, not average. A player averaging 60 yards does not produce 60 yards. Knowing whether that average comes from consistent 55–65 games or from alternating 20s and 100s changes the over/under decision completely, even though the average is identical.

Alternate prop lines

Books offer the same prop at several numbers — over 40.5, 60.5, 80.5 receiving yards, each at a different price. These are useful for expressing a view about the shape of a player's distribution rather than its centre.

They also carry more hold than the main prop line, which is already expensive. Treat them as a way to express a strong specific opinion, not as a default.

How WeBall grades props

Each prop resolves against that player's historical game logs for the relevant statistic. Counts — receptions, touchdowns, strikeouts — are fitted with a Poisson or negative binomial distribution depending on dispersion. Continuous quantities like passing and rushing yards use a normal approximation.

Two limitations are worth knowing. Props depend on per-player logs, so leagues without a dedicated collector have thinner coverage — see sports and leagues covered. And the model has no variable for game script, so a prop whose value depends on a team trailing is not capturing that. Both are listed on known limitations.

Players whose identity cannot be resolved to history with confidence are graded UNRATED rather than risk attaching a number to the wrong person.