Introducing the Coverage Execution Index

CEI Pro is here to isolate pure secondary technique from front-four and blitz pressure metrics.

I built CEI Pro to isolate pure secondary technique from front-four and blitz pressure metrics that can inflate EPA/Pass and DVOA. Traditional passing-efficiency data can be heavily skewed by sacks and high-variance turnovers, masking structural coverage failures on the backend.

CEI Pro strips the noise by grading five specific secondary pillars:

• Catch-point leverage (Win%)

• Down-to-down scheme efficiency

• Deep ball efficiency (20+ Comp)

• Open-field tackling (YAC/C)

• Forced Turnover Worthy throws (TOW)

The final metric standardizes this data against the rolling NFL average, establishing a true baseline for identifying which units are performing at an elite level, regardless of their pass rush. Since I'm using FTN, which includes DVOA, I'm applying the same logic: 20% = 20% better than the average defense.

I plan to bring back the weekly Data Download next week in a new format, at the midpoint of the NFL season. So be on the lookout.

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The Data

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*EPA and DVOA are there for comparison.

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Case Studies

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Carolina Panthers

On paper, the Carolina Panthers don’t look like an elite secondary. Digging deeper into their data tells a different story. The same was true last year.

Carolina’s secondary execution is elite, even with the major injuries they have faced this year. As before, the pass rush hasn’t helped the back end.

Carolina has one of the better tackling secondaries in football, allowing an NFL-low 3.74 Yards After Catch per Completion (YAC/C). They also rarely suffer major breakdowns, with a Wide-Open rate of 5.4%.

Though they rarely play man coverage, the Panthers still keep a lid on opponents’ passing attacks. CEI Pro isolates execution and shows when DBs are doing their job versus when the pressure picks up the slack.

With both Ejiro Evero and Jonathan Cooley now gone, it will be interesting to see if there is any regression. Stay tuned.

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Detroit Lions

If you look at traditional passing-yardage stats, the Detroit Lions have a “bad” secondary that gives up a ton of raw passing. But antiquated stats distort what is really going on.

Detroit is seeing more passing and ranks third in passes faced (no garbage time). Still, the Lions rank first in Win Rate (~50%), which factors in FTN’s Tight (TC) and Close Coverage (CC) rates.

Detroit's DBs live in a receiver’s hip pocket and tackle effectively when targeted (3.8 YAC/C). But their aggression is an issue, which hurts them.

They give up a 40% completion rate on throws over 20 yards. CEI captures this duality and weights it: sticky at the catch point, but vulnerable over the top.

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Data Glossary

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• Defensive Win%: Calculated by using Tight Coverage (TC) and Close Coverage (CC) rates.

• Separation%: Calculated by using Step Coverage (SC%), Open Coverage (OPEN%), and Wide Open (WO%) coverage rates.

• TC (Tight Coverage): Defender is in the receiver’s hip pocket (1 yard or less of separation) at the catch point.

• CC (Closing Coverage): Defender is rallying from depth and quickly closing space as the ball arrives.

• SC (Step Coverage): The receiver has 1 to 2 steps of clear separation from the defender.

• OPEN (Open Coverage): Receiver has 2 to 5 yards of clear separation.

• WO (Wide Open): No defender in the immediate vicinity (5+ yards of separation). This flags blown assignments and structural busts.

• Total YPD: Scheme-weighted Yards Per Dropback. Combines Man and Zone yield to measure down-to-down passing yardage efficiency.

• 20+ COM%: Completion percentage on targets traveling 20 or more air yards. Measures the defense’s explosive cap.

• YAC/C: Yards After Catch per Completion. The primary metric for secondary rally-and-tackle efficiency.

• TOW%: Turnover-Worthy Play Rate. Measures how often the coverage forces the quarterback into dangerous decisions, regardless of whether the defender actually catches the interception.

• EPA/DB: Expected Points Added per Dropback. A macro metric heavily influenced by sacks, pressure rates, and turnovers.

• Pass DVOA: Defense-adjusted Value Over Average. A macro per-play efficiency metric adjusted for opponent strength, down, and distance.

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