KC Joyner glossary

KC Joyner's curiosity for NFL play-calling and schemes led to his establishing a career in football research.

Originally Published: February 28, 2008
ESPN.com

KC Joyner's curiosity for NFL play-calling and schemes led to his establishing a career in football research. He likes to focus on performance-based metrics, measurements he uses to determine how well a player is doing in specific areas of his job. The following is a list of terms that form the basis for his analysis:

Bad decisions: A quarterback is charged with a bad decision when he does something with the ball that either leads to, or nearly leads to, a turnover. The most common bad decisions are forcing passes into coverage or staring at receivers.

Catchable pass: A pass that a receiver has a reasonable chance of catching.

Cornerback cushion: This metric tracks how effective a cornerback is when he lines up at the varying cushion depth levels (1, 2, 3, 5, 7 and 9-plus yards).

Coverage sack: A sack that occurs in the pocket more than three seconds after the snap.

Deep assist coverage: Coverage in which a safety is responsible for helping another defender cover a pass downfield. Compare to Direct coverage.

Depth level: A measurement of how far downfield a receiver was on a pass attempt. It is measured from the point at which the receiver touched the ball. Short passes are 1-10 yards downfield, medium 11-19, deep 20-29 and bombs are 30-plus yards downfield.

Direct coverage: Coverage in which a defensive player is directly and actively responsible for covering his man. Direct coverage can occur in either man or zone coverage. In zone coverage the defender has to be actively trying to cover the receiver for it to count as a direct coverage pass.

Forced incompletions: Any incomplete pass that a defensive back is physically responsible for causing. It is a combination of passes defensed, stripped/dropped passes and plays where a hit by a defensive back causes an incompletion.

Garbage sack: When one defensive player gets a sack due to the pass-rushing efforts of another defender. One typical example of this is when a defensive end crashes the pocket from the outside and forces the quarterback to step up into a well-blocked defensive tackle. The tackle was only able to get the sack because of the defensive end's pass rush, so he is credited with a garbage sack.

Good recognition sack: This type of sack is given when a defensive player makes a sack because he didn't bite on a fake by the offense that was supposed to take him out of position. A good example of this is when a defensive end reads a bootleg pass correctly.

Individual effort sack: A sack where a defensive player beats an offensive player one-on-one for a sack.

Interception types: This metric is designed to give more information as to why an interception occurred.

Missed passes: Inaccurate or dropped passes that cause an incompletion. Missed passes are used to measure how successful a QB/WR/TE could have been if not for the mistakes. They also help measure how lucky a cornerback was in coverage.

Near interception: Near interceptions are either dropped interceptions or interceptions that landed close enough to a defender that he could have had a chance to catch the ball had luck been on his side.

Not at fault interceptions: Interceptions that occur for reasons other than bad decisions or inaccurate passes.

"Other" sacks: The type of sack that is credited when a sack doesn't fit into any of the other categories. The most common "other" sack is the gimme sack. Gimme sacks most often occur when a quarterback trips over a lineman's foot on his drop and is downed by a defensive player.

Passing tree: The types of route a receiver can run, expressed in a format that resembles a tree.

Point of attack success percentage: The percentage of time that a defensive lineman or linebacker defeats a block on a running play directed at his gap. A point-of-attack run can be loosely defined as which blocker/defender the running back ran behind when crossing the line of scrimmage.

Productivity by route type: This metric tracks the performance of a wide receiver, cornerback or quarterback when a play involves a certain type of route.

Pursuit plays: Plays where a defensive lineman either chases a play down from the backside of the play or goes 5+ yards downfield to make a tackle.

Pursuit sack: A type of sack that occurs when the quarterback is scrambling out of the pocket but is still looking to throw the ball downfield when he is sacked. Compare to run sack.

Run sack: This type of sack is credited when a quarterback starts to run after dropping back to pass the ball. The quarterback must be out of the pocket and pull the ball down, tuck it away and be running towards the line of scrimmage for a play to be noted as a run sack.

Scheme sack: A sack where a defensive player beats an offensive player due to running a stunt or a blitz.

Stripped/dropped pass: A pass that a receiver starts to catch but then has the ball stripped away by the cornerback.

Success Percentage: The percentage of plays a player does something successful with the ball. Successful plays include completions (for offensive players), incompletions (for defensive players) and penalty plays that go in the player's favor.

SYPA (Success percentage X Yards Per Attempt): A metric that combines both success percentage and YPA in an effort to measure a player's overall effectiveness.

TYPCA (Total Yards Per Catchable Attempt): A metric that measures the number of yards a receiver gains when a catchable pass is thrown his way. May 12, 2006 article

Weighted bad decision percentage: Bad decisions are given point totals based on the amount of damage they cause. Weighted bad decisions are those point totals expressed as a percentage of total pass attempts.

YPA (Yards Per Attempt): A quick barometer of a quarterback/wide receiver/tight end's efficiency. For wide receivers/tight ends, the most basic description of an attempt is any pass that is intended for a receiver that doesn't fall into the "non-catchable" pass category (throwaway passes, passes knocked down at the line of scrimmage, etc.).