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January 25, 2018

MILMIA

MIL won this trade +$173.6M surplus MIL won this trade +34.5 WAR
MILMIL David Stearns net +$173.6M net +34.5
received +$90.4M+$45.6M ± $54M expected surplus · +$140.8M realized received 23.6 ± 7 expected · 28.6 realized WAR
Playoff odds: this deal moved MIL's 2018 odds 14% → 57% (+42.5 pts) — how trade timing is graded ↗
receives — most valuable first
Christian YelichOF·27y·L/R
+$90.4M+$45.6M± $54M exp surplusrealized +$140.8M 23.6± 7 exp WARrealized 28.6
Prior
league baseline (track record outweighs draft pedigree) → 0.25/yr
Evidence
recent form 4.2/yr over 2.3 seasons
Talent
2.87/yr blended
Horizon
9.0 control yrs × 0.91 age decline
MIAMIA Michael Hill net −$173.6M net -34.5
received +$33.6M+$33.6M ± $114M expected surplus · −$32.8M realized received 10.5 ± 14 expected · -5.9 realized WAR
Playoff odds: this deal moved MIA's 2018 odds 2% → 0% (-1.3 pts) — how trade timing is graded ↗
receives — most valuable first
Lewis BrinsonOF·24y·R/R
+$16.8M+$16.8M± $55M exp surplusrealized −$19.2M 4.5± 7 exp WARrealized -3.4
Prior
BA #18 pedigree (2018) → 1.02/yr
Evidence
recent form -0.9/yr over 0.1 season
Talent
0.82/yr blended
Horizon
5.5 control yrs
Monte Harrison#75OF·23y·R/R
+$8.0M+$8.0M± $58M exp surplusrealized −$0.8M 2.5± 7 exp WARrealized -0.1
Prior
BA #75 prospect (2018) → 0.46/yr
Evidence
no MLB track record — leans on pedigree
Talent
0.46/yr blended
Horizon
5.5 control yrs
Isan Díaz#932B/3B·22y·L/R
+$7.2M+$7.2M± $58M exp surplusrealized −$14.4M 2.3± 7 exp WARrealized -2.7
Prior
BA #93 prospect (2017) → 0.42/yr
Evidence
no MLB track record — leans on pedigree
Talent
0.42/yr blended
Horizon
5.5 control yrs
Jordan YamamotoP·22y·R/R
+$1.6M+$1.6M± $58M exp surplusrealized +$1.6M 1.2± 7 exp WARrealized 0.3
Prior
#356 overall draft pick — at the league baseline → 0.21/yr
Evidence
no MLB track record — leans on pedigree
Talent
0.21/yr blended
Horizon
5.5 control yrs

Each player is valued on what he was expected to produce at the time of the trade, versus what he actually produced for his new team.

Expected WAR blends a player's pedigree (Baseball America rank / draft slot, or a baseline) with his recent track record, projected over the years of team control acquired. The ± band is the uncertainty — wide for unproven prospects, tight for established veterans. Surplus values that production at the FA market price of a win (~$8M/WAR) minus salary — so cost-controlled players carry large surplus and expensive ones little, even at the same WAR. Who won is descriptive, not a skill claim: ~99% of a trade's outcome is unforeseeable at the time.

Historically these expected values are unbiased and land within ±2 WAR of reality 75% of the time — yet the side the model favors actually comes out ahead only 53% of the time. The grade is a calibrated bet, not a prediction. Why trades are an efficient market →