Model Versions — what changed, and when

A running changelog for the trade-grading model. We'd rather show our work than silently move the numbers.

v1.1 — Role-specific pricing (July 2026)

The tier-adjusted $/WAR curve was calibrated on all roles pooled together — fine for hitters, but it systematically mispriced pitchers by role. A dominant closer's θ (expected WAR/yr) tops out around 0.5-1.5 simply because he throws 60-70 innings a year, not because he's replacement-level — so the pooled curve was pricing elite closers like part-time role players. Added a role-specific correction on top of the existing tier table, calibrated the same way (real FA-signing AAV vs. θ, empirical-Bayes shrunk by sample size):

• Closers +106%, starters +56%, outfield +28% — all real, large-sample underpricing in the old pooled model.
• Generic (non-closer) relievers: no change. The whole gap was the closer/saves role specifically, not relief pitching in general — an important distinction the pooled analysis had been hiding.
• Catchers and infielders adjusted down modestly (−6% to −20%) — the flip side of the same pooled-curve distortion.

Full table and methodology: Grading Trades. The correction only applies once a player has a real, games-evidenced role — an unproven pitching prospect isn't defaulted into the starter premium just because he hasn't been used in relief yet.

v1.0 — Tier-adjusted $/WAR (launch)

The original model: WAR delivered by a star prices at a real premium over WAR delivered by a replacement-level player (0.65× to 1.60× the league-average $/WAR, by talent tier), calibrated against FA-signing AAV data. See Grading Trades for the full tier table.

Fit on full team-seasons (≥100 games), 1985–2024/25. All figures are franchise-level outcomes credited to the decision-maker in the relevant year — see the GM profiles for per-executive numbers.