Player props, and why they're softer

Prop markets are thinner, dearer and less efficient than game lines. Every one of those three facts matters, and they do not all point the same way.

Player props are bets on an individual's statistics rather than the game result. They are thinner, dearer and less thoroughly priced than game lines — and all three of those facts matter, but they do not all point the same way.

How a prop is priced

A game line is one number that hundreds of professionals argue about all week. A prop line is one of thousands a book must post for the same slate, often generated by a model with a trader glancing at it.

A projection for the player's statistic, from usage, pace, matchup and recent minutes.
A distribution around it — how likely each outcome is, not just the average.
A line and a fee. The line goes near the middle; the fee goes on both sides, and it is larger than on a game line.

The projection is usually decent. The weak point is the distribution, and specifically what happens when a player's role changes — an injury elsewhere in the lineup, a blowout, a pitcher on a limit.

The three things that make props different

	Game line	Player prop
Typical hold	~4.5%	6-8%, sometimes more
Limit	Thousands	Often a few hundred, or less
Attention per market	Enormous	Very little
Moves on news	Within seconds	Sometimes minutes, sometimes not at all

The last two rows are the opportunity. The first two are the cost. A prop market can be genuinely soft and still not be worth betting, because the fee is large and you cannot bet enough into it to matter.

A large prop edge is usually a data problem

An 11% edge on a rebounds line almost always means the two prices are not the same bet — a different line, a different period, a player who has just been ruled out, or a stat defined differently by the two books. Check before betting, not after.

Where the soft spots actually are

Late lineup news. A starter ruled out changes the usage of four teammates. Game lines reprice immediately; their props sometimes lag.
Second-order roles. A backup's line is priced off small samples and moves less than it should when the situation changes.
Alternate numbers. The main line is watched; the alternates around it are often stale relative to it.
Shopping. Prop lines differ between books more than game lines do — half a rebound or a quarter of a yard is a real difference.

Note what is *not* on that list: an opinion that a player is due, or in form, or matched up well. Those are already in the projection, and they are the part the book does well.

The cost of betting them

Props are where accounts get limited fastest. Low limits mean a book notices unusual money immediately, and prop bettors who win are cut sooner than game-line bettors who win.

They are also the raw material for DFS pick'em, which prices the same projections under completely different rules — and that is the next lesson.

Every player prop VigWatch prices, with the no-vig fair line beside each one. Open the props board.