Football Analytics Glossary
Every stat Muffed uses on air, explained without jargon — and with a live leaderboard under most definitions so the examples are never out of date.
EPA (expected points added)
Expected points added measures how much a single play changed a team's expected points on the drive.
EPA per dropback
EPA per dropback is expected points added divided by every pass attempt, sack and scramble — the cleanest single measure of quarterback play.
Success rate
Success rate is the share of plays that gained positive expected points — roughly, plays that kept the offense ahead of the chains.
CPOE (completion percentage over expected)
CPOE is a quarterback's completion percentage minus the completion percentage expected on his throws, given depth, receiver separation and pressure.
ANY/A (adjusted net yards per attempt)
ANY/A is passing yards with touchdowns, interceptions and sack yardage folded in, divided by attempts plus sacks.
RYOE (rushing yards over expected)
RYOE is the yardage a back gained beyond what the blocking and the defensive alignment predicted.
Target share
Target share is the percentage of a team's throws that go to one receiver.
Air yards share
Air yards are the distance a pass travels past the line of scrimmage, thrown or caught; air yards share is a receiver's cut of his team's total.
WOPR (weighted opportunity rating)
WOPR folds target share and air yards share into one opportunity number: 1.5 times target share plus 0.7 times air yards share. Every qualifying 2025 pass catcher ranked, with both inputs shown.
aDOT (average depth of target)
aDOT is the average distance past the line of scrimmage a player's targets travel.
YAC over expected
Yards after catch over expected is the yardage a receiver gained after the ball arrived, minus what the tracking data predicted from the situation.
Separation
Separation is the distance in yards between a receiver and the nearest defender when the ball arrives.
Pressure rate
Pressure rate is the share of dropbacks on which a quarterback was hurried, hit or sacked.
Blitz rate
Blitz rate is the share of dropbacks a defense rushed five or more.
Man and zone coverage splits
Man coverage assigns a defender to a receiver; zone assigns him to an area.
PROE (pass rate over expected)
PROE is how much more often a team passed than the game situation called for.
Stacked box rate
Stacked box rate is the share of a back's carries run against eight or more defenders near the line.
Half-PPR (and how it differs from full PPR)
Half-PPR awards half a point per reception; full PPR awards one.
The usage gap (snaps versus production)
The usage gap is a player's positional finish minus his positional snap-share rank, so a negative number means he outproduced the snaps he was given.
Pythagorean wins
Pythagorean wins estimate how many games a team should have won from its points scored and allowed.
Stickiness (what repeats and what does not)
Stickiness is how strongly a stat in one season predicts the same stat the next.
Snap share
Snap share is the percentage of his team's offensive plays a player was on the field for.
Pass-snap share
Pass-snap share is the percentage of his team's dropbacks a player was on the field for.
YPRR (yards per route run)
YPRR divides receiving yards by routes run — charted data Muffed does not license, so it publishes no YPRR. Receiving yards per pass snap is the closest verifiable stand-in, and the 2025 board is here.
Availability (the “stayed” rate)
Availability is the share of his team's games a player actually appeared in, measured across seasons rather than one.
Handcuff
A handcuff is the backup who inherits the workload if a starter goes down — almost always a running back, because backfields concentrate touches in one...
Play-action rate
Play-action rate is the share of an offense's dropbacks that came off a run fake. All 32 offenses ranked for 2025, with the dropback counts behind each rate.
Pre-snap motion rate
Pre-snap motion rate is the share of an offense's plays with a man moving before the snap. All 32 offenses ranked for 2025, with the play counts behind each rate.
Drop rate
Drop rate is drops as a share of catchable targets rather than of all targets.
Contested catch rate
Contested catch rate is the share of contested targets a pass catcher caught. The 2025 board for receivers and tight ends, with the number of contested balls behind every rate.
Interception-worthy throws
An interception-worthy throw is one a charter judged should have been intercepted, whether or not it was.
Quarterback-fault sacks
A quarterback-fault sack is one a charter judged the passer caused rather than his protection.
Intended air yards (IAY)
Intended air yards are the total distance a quarterback's throws travelled past the line of scrimmage, caught or not — the record of what an offense tried to do.
Deep ball rate
A deep ball is a pass thrown 20 or more yards past the line of scrimmage. Deep ball rate is the share of a quarterback's attempts that went that far — what he tried, not what he completed.
QB Composite Rating
A QB Composite Rating weighs six measurements of quarterback play into one number, expressed in standard deviations above an average qualifying starter. Muffed's version weights expected points at 65 percent.
Screen pass rate
A screen pass is a throw behind or at the line to a receiver with blockers set up in front of him. Screen pass rate is the share of an offense's dropbacks that were one.
No-huddle rate
No-huddle rate is the share of an offense's scrimmage snaps run without a huddle first — a tempo choice, and not the same thing as playing fast.
RPO rate
A run-pass option (RPO) is a play where the quarterback decides after the snap whether to hand off or throw. RPO rate is the share of an offense's plays called that way.
Light box rate
A light box is six or fewer defenders near the line of scrimmage at the snap. Light box rate is the share of a running back's designed runs that met one.
Throwaway rate
A throwaway is a pass thrown out of bounds or into the ground on purpose to avoid a sack or a turnover. Throwaway rate is the share of a quarterback's dropbacks that ended that way.
Catchable throw rate
A catchable throw is a pass the intended receiver could reasonably have caught, whether or not he did. Catchable throw rate is the share of a quarterback's attempts that were catchable.
Out-of-pocket rate
A quarterback is out of the pocket when he has left the area his blockers form around him. Out-of-pocket rate is the share of his dropbacks on which he did, by design or escape.
Time to throw
Time to throw is the average number of seconds from the snap to the moment a quarterback releases a pass, measured by NFL Next Gen Stats tracking.
Aggressiveness
Aggressiveness is NFL Next Gen Stats' share of a quarterback's attempts thrown into tight coverage — a defender within a yard of the receiver when the ball arrived.
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