IPV Explained

Isolated Player Value (IPV) is a measure of a quarterback's performance that accounts for factors outside of his control and isolates only his individual value. The values are based on Expected Points Added (EPA)* and are scaled with an IPV score of 0 representing an average NFL starter. A quarterback's IPV represents how many points an average NFL team would score with him at quarterback compared to how many they would score with the average NFL starter. IPV is recorded as Total IPV and IPV/Game , which divides Total IPV by the number of plays recorded and multiplies the result by 32.7 (the average pass attempts per game in 2024). It is also divided into Decision Making, Handling Pressure, Creativity and Execution scores that represent different aspects of quarterback play and their impact on a player's IPV.

*play-by-play EPA data is sourced from https://rbsdm.com/stats/box_scores/

Every pass attempt, including sacks and throwaways, of every game from the 2024-25 NFL regular season and as much game film on 2025 NFL Draft prospects as is available to the public was analyzed. NFL game film is from NFL Pro , college game film is from Caddy's Cutups .

On each play, I chart the outcome the QB generates by recording the accuracy of his throw or if the QB is sacked, sacked and fumbles or throws the ball away. Accuracy is categorized as follows:

• Pinpoint — a pass thrown with the necessary accuracy, velocity, placement and anticipation and is a catchable ball that the defense cannot make a play on
• Catchable — a pass thrown in a spot where it can be caught and cannot be broken up or intercepted but the placement is imprecise, failing to maximize the potential for yards after the catch or making the catch attempt more difficult than it needs to be
• Fifty-Fifty — a pass thrown in a spot where both the receiver and defender can make a play on the ball
• Safe — a pass that cannot be caught but is successfully placed away from the nearest defenders
• Inaccurate — a pass that cannot be caught and is not intentionally placed away from the nearest defenders
• Dangerous — a pass that should be intercepted

I also chart the decision I would expect an NFL starting caliber QB to arrive at on each play given the offensive playcall, defensive coverage, separation his receivers are able to create and pressure the defense is able to generate. Decisions include the following:

• Targets , which are categorized by their passing window and Air Yards (distance from the line of scrimmage to the catch point) with horizontally difficult throws (generally those thrown from the middle of the field to outside the numbers or further) also being noted
• Throwaway
• Sack
• Sack fumble — I know a QB doesn't always "decide" to take a sack and definitely not to fumble but sometimes these are unavoidable and in those cases I record them as the expected decision

• Wide — Wide open passing windows are targets where the pass simply needs to be on-target and doesn't require additional velocity, touch, placement or anticipation.
• Open — Open passing windows are targets where there is sufficient separation between the receiver and the nearest defenders for an NFL-caliber QB to easily avoid throwing a pass that the defense can make a play on but in which the throw requires additional velocity, touch, placement or anticipation.
• Tight — Tight passing windows are targets that require an additional level of precision as the QB needs to fit the ball in between multiple defenders in close proximity to the intended target or away from a primary defender playing tight man coverage. A big enough passing window remains that an NFL QB has a legitimate chance of throwing a pinpoint pass but it requires a quality pass and the likelihood of fifty-fifty, inaccurate and dangerous passes are increased.
• Closed — Closed passing windows are targets where a defender is in good enough position to make a play on even a well thrown ball.

I also record the pressure the QB is under at the point where the expected decision should be made. Pressures that come from a QB hanging on to the ball too long or that he creates due to poor pocket management are not recorded.

• Clean pocket (C) — QB is able to fully step into his throw without taking a hit or altering his dropback significantly. If a QB leaves a clean pocket prematurely and creates pressure for himself, the pressure is still graded as a clean pocket.
• Pressure (P) — A pressure occurs when a rusher is unable to sack the QB but alters his process significantly, forcing him to maneuver around him or preventing him from stepping into a throw to the expected target, creating an increased difficulty in arriving at the expected decision and throwing a pinpoint pass.
• Free rusher (F) — A free rusher is one who breaks free of his blocking or is unblocked and could hit or sack the QB given the timing of the expected decision. Free rushers on plays where the expected decision is a quick pass may be charted simply as pressures and can even be considered a clean pocket on plays where rushers are designed to be unblocked (e.g. screen passes). Plays with free rushers are more likely to result in sacks.

Multiple pressures may be charted on a single play (e.g. PP, FP, FF). If multiple rushers create pressure but are coming from the same angle and have the same effect on the QB, they are not charted separately.

On each play, I chart the number and type of reads that the QB goes through or would have to go through to arrive at the expected decision. Misreads are recorded when QBs do not read the defense correctly. Types of reads are as follows:

• Open — Open reads involve a QB recognizing that his receiver has favorable leverage against the primary defender responsible for covering him. Open reads have a lower misread rate and a higher misread EPA due to the fact that QBs can still achieve a positive outcome if they have enough time to find another target.
• Covered — Covered reads involve a QB identifying that throwing to a potential target would likely result in a dangerous pass. Covered reads are not charted every time a QB "turns down" a covered receiver but only in situations with a greater likelihood to result in an NFL-caliber QB throwing a dangerous pass. Examples include ancillary defenders dropping into passing windows and primary defenders showing a favorable coverage look pre-snap then shifting post-snap. Covered reads have a higher misread rate and low misread EPA because misreads often result in dangerous passes.
• Hot — Hot reads involve a QB identifying that the defense is bringing 1 more rusher than he has blockers for and that he has to throw quickly to his "hot" receiver. Hot reads have a lower misread rate and a low misread EPA because misreads often result in sacks.
• Ancillary — This is a catch-all category for all other reads not described by the previous 3 categorizations. It typically describes reading players ancillary to the primary defender responsible for coverage of an intended target but whose positioning the QB still needs to be aware of in order to throw a pass with both pinpoint accuracy and placement. "Turn downs" of covered receivers that don't rise to the difficulty or dangerousness of covered reads are charted as ancillary reads. A pure progression play where a QB progresses to his 3rd read and a play where a QB throws to the first receiver he looks at but has to recognize positive leverage with the primary defender responsible for his intended target and the positioning of 2 ancillary defenders would both be charted as "AAO" (2 ancillary reads and 1 open read), ensuring the ability to accurately describe the processing ability of QBs in different offenses. Ancillary reads have a moderate misread rate and EPA.

"Holding" a defender refers to a QB keeping a defender in place to prevent him from breaking on the intended target. The most common example is a QB holding a single-high safety in the middle of the field before throwing a go route on the outside. I record these as simply a single open read since they are typically easy, pre-determined decisions that QBs at all levels of football can make. More difficult reads where the defense changes their look post-snap and complicates the process of holding defenders are recorded accordingly.

"Reading" a defender refers to a QB recognizing a defender's leverage and positioning and his impact on the advisability of a particular decision. I record "high-low" reads where a defender is put in conflict and forced to choose between 2 receivers as ancillary reads since they are in between open and covered reads in terms of difficulty and misread EPA.

"Manipulating" defenders refers to a higher level of processing that involves a QB creating open windows by moving defenders out of the passing lane with his eyes. When a QB manipulates a defender, it is recorded as an ancillary read and I also increase the passing window by one level (e.g. from open to tight). This ensures that QBs who can fit the ball into tight windows with mental processing rather than arm talent are properly valued.

A QB's Adjusted EPA on a given play is the average EPA value of the outcome the QB produced as defined by his Target, Accuracy and Air Yards. Pinpoint passes can be dropped, resulting in a negative EPA that doesn't reflect the QB's performance, while unexceptional short passes can result in massive EPA values if the receiver gets a lot of yards after the catch. Adjusted EPA controls for this and awards the QB the EPA value he deserves given the value of his contribution to the play.

A QB's Expected EPA on a given play is a representation of how well the average NFL starter would perform in the same situation the QB faced on that play. It is derived by calculating the expected misread, sack, non-misread negative, creativity, pinpoint, catchable, fifty-fifty, safe, inaccurate and dangerous rates and EPA values on a given play.

The rate at which the read(s) required to arrive at the expected decision on a particular play result in a misread and the average EPA when misreads occur are calculated to determine the average NFL starting QB's EPA due to misreads on a particular play. The influence of pressure on misread rate and EPA is considered.

The rate at which the pressure a QB faces on a particular play results in a sack and the average EPA of a sack are calculated to determine the average NFL starting QB's EPA due to being sacked on a particular play. The influence of reads on sack rate is considered. These do not include sacks taken as the result of misreads, which would be counted under misread rate and EPA.

Non-misread negatives refer to negative plays in which the QB's decision differs from the expected decision but there is not a misread or sack recorded. Examples include a QB throwing the ball away prematurely when he had time to read the defense and find an open man downfield and a QB trying to extend a play resulting in an inaccurate or dangerous pass instead of throwing the ball away. The effects of the expected decision, pressure and reads are considered to calculate the expected non-misread negative rate and average EPA of non-misread negatives on a given play.

Creativity refers to positive plays in which the QB's decision differs from the expected decision. Examples include a QB using his athleticism to avoid a sack or extend a play and generate a better outcome. The effects of the expected decision, pressure and reads are considered to calculate the expected creativity rate and average creativity EPA on a given play.

The rates in which a QB is able to achieve each level of accuracy on a given throw are calculated. The average EPA values of throws at the expected accuracy level into the expected passing window in the expected range of air yards are also calculated. The effects of the passing window, air yards, horizontally difficult throws, pressure and reads on accuracy rates are all considered.