2023 Free Agent Center Rankings

Projecting NFL Plus/Minus value added for the 2023 center free agent class

The 2023 offseason has begun, with free agency moves already happening. Officially, the window for signing unrestricted free agents begins on March 15th with the start of the new league year. But already teams have an opportunity to extend their own free agents, and released players also are available. The franchise tag window - another important tool for retaining elite players - goes from February 21st to March 7th.

Obviously you care about more than simply the next year’s value for players signed to multi-year contracts, but it’s increasing difficult to project performance beyond the next season for players switching teams, and subsequent performance is highly correlated. In reality, most free agent signing provide most of their value to their new teams in the first season, which is why even longer term contracts are primarily structured as glorified one-year deals with a little extra guaranteed money.

This analysis using ensemble modeling, or combining multiple model types to reduce noise while gaining incremental benefits in prediction accuracy. Specifically, the projections use linear and tree-based models, in roughly equal proportion. The key metric of determining value is my NFL Plus/Minus figure, which uses advanced stats, clustering and historical on-off splits to estimate player value in a universal, points-based figure.

In this analysis, I’l detail my methodology for projecting 2023 value for free agents. I began by identifying some potential values among wide receiver free agents earlier this week, then turned to offensive tackles and guards. In this article, I move on to centers, who share some similarities with their offensive line mates on the inside, but lose some relative value due to being a single-starter position. The primary difference is the respective availability in free agency for tackles and interior linemen, the latter being relatively plentiful. In a macro look at free agency, I found that guards and centers are the best position to target in free agency, with the offensive line franchise tag number lowering team leverage in negotiating extensions.

For centers, the model features (or independent variables) are, in order of importance:

• Previous-year pass blocking NFL Plus/Minus per game

• Previous-year run blocking NFL Plus/Minus per game

• Year-before-last run blocking NFL Plus/Minus per game

• Draft position

• Year-before-last pass blocking NFL Plus/Minus per game

• Age

• Games played (last two years)

Two-years trailing run blocking is even more important for centers than guards, and it was much less important than pass blocking for tackles. There are two additional features (“new team” and “trade”) to differentiate free agent projections on a new team versus players who are in the middle of contracts with the same team or acquired via trade. As we saw with my macro analysis of free agency by offensive position, players who switch teams via free agency generally perform worse than the equivalent player who remains with the same team, and also underperform players acquired via trade.

TIER 1 FREE AGENT CENTERS

The “tier 1” table below lists six centers, with their 2023 points-added projection (“Proj +/-), actual numbers for the last two seasons, games played the last two seasons, snap percentage last year, age as of Week 1 of the 2023 season, and draft position. These six center have above average projections for value added in 2023.

You can find all the free agent projections on the paid subscriber Google Sheet. I’ll add the other positions as I work through the process this week.