2023 NFL Offseason: Improvement Index for all 32 teams

Projecting point-differential gains and losses based on offseason moves for every NFL team

Four years ago, I developed the Improvement Index — a way to quantify the value gained and lost by each team in the offseason.

The index is built on the rigorously researched NFL Plus/Minus metric, which translates player values into intuitive, concrete and position-agnostic currency of points added or lost. The index is the point differential gain or loss each team during the offseason, beginning with the first player cuts in early February.

The model behind the Improvement Index projects the numbers of snaps and per-play efficiency for each player in every facet of offensive and defensive play: passing, rushing, receiving, blocking, pass rush, run defense and coverage. These models were trained on years of historical data, going back to 2006. The model incorporates player- and team-level assumptions based on each player’s prior performance, team coaching tendencies, forecasted opponents, and championship odds. These features help the model estimate the likely allocation of snaps among each position group and the likely points-added/lost per snap for each player based on that usage and historical trends.

Some teams will move on the improvement index even if they haven’t added or dropped an influential player, as the total point differential gains must net to zero, i.e. one team’s point differential gains must be offset by others’ losses, and vice versa.

Also, the team losing a player will not have the opposite point-differential gain/loss as the team gaining a player, as different quality of players will be gaining and losing snaps on those teams, e.g. the Saints do not gain as many points by signing Derek Carr as the Raiders lose, because he’ll be replacing a better quarterback in New Orleans (Andy Dalton) than is left to fill the void in Las Vegas (Jarrett Stidham).

Each day, the Improvement Index plot below will be updated, along with a table of all the players joining a new team, with estimates for points-added above a replacement-level player at their positions. It’s important to remember that the points above replacement level number will not match the team gains, as the latter will mostly be based on snaps shifting between better than replacement-level players.

Here is the movement in the index, generated by the confirmed transactions, through 12:00 p.m. Wednesday, March 23rd. This includes dozens of released players.

The full list of player movement and value added is available on the Unexpected Points subscriber Google sheet.