NFL Prop Betting Glossary

Markets and Pricing

Player prop

A betting market on one player’s statistical result in one game, such as receiving yards or completions, instead of on the game’s outcome.

Over / Under

The two sides of a prop. Over wins when the player finishes above the posted number, under when he finishes below it.

Push

A tie between the result and the line, which returns the stake. Half-point lines such as 54.5 exist specifically to prevent pushes.

Vig (juice, margin)

The sportsbook’s built-in commission, priced into the odds instead of charged separately. Two sides at -110 imply about 105 percent combined, and that surplus is the theoretical hold.

Implied probability

The win chance a price corresponds to. A -110 price implies 110 ÷ 210, or roughly 52.4 percent, which is also the break-even win rate at that price.

Lines and Movement

Opening line

The first number a sportsbook posts for a prop. It’s fixed once posted and serves as the baseline for measuring how far a market has travelled.

Current line

The number posted right now, which can keep changing until kickoff. Comparing it with the opening number shows how expectations have shifted during the week.

Closing line

The final number before kickoff, after every injury report and wager has been absorbed. It’s the market’s best-informed estimate of that prop.

Closing line value (CLV)

The comparison between the number you took and the number that closed. It describes the quality of the price you obtained, not whether the bet won.

Line movement

A change to a prop’s threshold, its price, or both. A move signals that the book’s expectation changed. It doesn’t establish what will happen in the game.

Reverse line movement

When a line moves against the side holding most of the bets, indicating that something other than ticket count is driving the price: wager size, exposure, or information.

Sharp action

Wagers from bettors a sportsbook considers informative enough to update its number instead of simply rebalancing. No public feed identifies who placed a bet, so sharp action is inferred, never observed.

Opportunity

Opportunity

The chances a player is likely to get: attempts, carries, targets, routes, and snaps. It’s the floor everything else is built on, and the first of the four research questions.

Snap share

The percentage of his team’s offensive plays a player is on the field for. A blunt but reliable indicator of whether a role is growing or shrinking.

Route participation

How often a receiver runs a route on his team’s pass plays. A player can hold a high snap share while running few routes, which caps his realistic target volume.

Target share

The percentage of a team’s targets going to one receiver. It converts more directly into receptions than into receiving yards.

Game script

How a game is expected to unfold, particularly whether a team is likely to lead and run or trail and throw. It shapes the size of the opportunity pool before any individual role is considered.

Pace

How quickly an offense runs plays. Faster pace produces more total plays, which raises the ceiling on volume-driven props for everyone involved.

Pass rate

How often a team throws rather than runs. Together with pace it determines how many dropbacks a game is likely to generate.

Efficiency

Efficiency

What a player’s chances are typically worth: yards per attempt, catch rate, yards per target. The second research question, and the source of most week-to-week variance in yardage props.

Average depth of target (aDOT)

How far downfield a player is targeted on average. It’s the quickest way to tell an underneath possession role from a downfield one.

Air yards

The distance a pass travels in the air toward its intended target, counted whether or not the pass is caught. It separates opportunity created downfield from yardage actually produced.

Yards after catch (YAC)

Yardage gained after a reception is made. Along with target depth, it’s why a yardage prop swings harder than the catch count underneath it.

Explosive play

A single large gain, typically defined as a run or reception past a set yardage threshold. A handful of them can carry a yardage total on a night the underlying volume was ordinary.

Where to Go Next

These terms fit together into a research sequence: the four questions covers how to move from opportunity through efficiency, matchup, and reliability. How sportsbooks set prop lines explains where the number came from, reading line movement explains what happens to it during the week, and the comparisons on passing yards versus completions and receptions versus receiving yards show the opportunity-efficiency split applied to real markets.

Sources

This glossary spans two vocabularies, so the sources come in two halves: sportsbooks for the pricing terms, football data providers for the usage and efficiency terms.

• DraftKings Sportsbook, How to Read Odds is an operator's own explanation of odds, price, and the margin priced into both sides, which covers the vig and implied-probability entries.
• Pinnacle, What Is Closing Line Value? defines closing line value and the treatment of the closing number as the market's best-informed estimate.
• NFL Next Gen Stats defines air yards, average depth of target, yards after catch, snap share, and target share as tracked measures.
• nflfastR publishes open play-by-play data as part of the community nflverse project, where most of these usage and efficiency measures are computed publicly.
• NFL official statistics defines how the underlying counting stats are credited in a game.

Prop Lab is not a sportsbook and has no affiliate or commercial relationship with the operators linked above.