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December 4, 1990

SFG⇄OAK

SFG won this trade +$9.6M surplus SFG won this trade +2.4 WAR
SFGSFG Al Rosen net +$9.6M net +2.4
received +$14.4M+$14.4M ± $31M expected surplus · +$5.6M realized received 3.1 ± 4 expected · 2.8 realized WAR
Playoff odds: this deal moved SFG's 1991 odds 5% → 5% (+0.3 pts) — how trade timing is graded ↗
receives — most valuable first
Darren LewisOF·23y·R/R
+$14.2M+$14.2M± $29M exp surplusrealized +$5.6M 2.9± 4 exp WARrealized 2.8
Prior
Composite #71.0 pedigree (Baseball America #71 (1990)) — fell off 1 list since, regressed → 0.25/yr
Evidence
recent form 2.5/yr over 0.2 season
Talent
0.53/yr blended
Horizon
5.5 control yrs
Pedro Pena
+$0.3M+$0.3M± $11M exp surplusrealized +$0.0M 0.2± 1 exp WARrealized 0.0
Unidentified minor-league throw-in — valued at the ~0.2 WAR base rate (most produce nothing)
OAKOAK Sandy Alderson net −$9.6M net -2.4
received +$0.0M−$2.4M ± $13M expected surplus · −$4.0M realized received 1.2 ± 2 expected · 0.4 realized WAR
Playoff odds: this deal moved OAK's 1991 odds 6% → 6% (-0.3 pts) — how trade timing is graded ↗
receives — most valuable first
Ernie Riles3B/SS·30y·L/R
+$0.0M−$2.4M± $13M exp surplusrealized −$4.0M 1.2± 2 exp WARrealized 0.4
Prior
no pedigree — league baseline → 0.21/yr
Evidence
recent form 1.2/yr over 1.9 season
Talent
0.81/yr blended
Horizon
1.5 control yr × 0.96 age decline

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 (composite top-100 rank / draft slot, or a baseline) with his recent track record, projected over the years of team control acquired. The ± figure is a historically calibrated predictive standard deviation, measuring how widely comparable forecasts have missed around their expected value. 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.

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Decision-maker records extend to 1933; resource-controlled WAR and payroll metrics cover 1985–2026. Data sources include FanGraphs, Baseball-Reference, the Chadwick Bureau register, the Lahman Database, prospect rankings from Baseball America, MLB Pipeline, and FanGraphs, and public payroll records. Transaction and trade data was obtained free of charge from and is copyrighted by Retrosheet. Executive birth/death data via Wikidata (CC0).
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