HOW WE SCORE TRADES


A team’s score counts only what its acquired players did in its uniform. Whatever those players did before the trade, or for any team that came after, belongs to someone else’s ledger.


THE FORMULA

For each player a team received:

Player Score = Win Shares
             + (Playoff Win Shares × 1.5)
             + Championship Bonus (contribution-weighted)
             + Accolade Bonus

Sum the players. Compare the sums. The larger one wins — but only past a 1.5-point margin. Inside that margin we call it even, because a single rotation season can swing it.


WIN SHARES

Dean Oliver’s stat. It divides team wins among the players who produced them. One Win Share is roughly one win. The data goes back to 1977.

The number is team-dependent on purpose: a 25-point scorer on a 22-win team has fewer wins to claim than the same player on a 55-win team.

We track Box Plus/Minus but don’t use it in the grade. It is the metric for shorter windows — early-career players, partial seasons, anywhere playoff Win Shares haven’t accumulated yet.


PLAYOFF WIN SHARES × 1.5

The same calculation, applied to the postseason, weighted by half again. A trade that took its team to the conference finals produced more than one that ended on a Tuesday in April.


CHAMPIONSHIP BONUS

Championship Bonus = 5.0 × (Player’s Playoff WS ÷ Team’s Total Playoff WS)

A title is worth five points, distributed by playoff workload. Rings count for the whole roster, weighted by who did the work.


ACCOLADE BONUS

Awards catch what the box score misses. The defensive side of Win Shares is the weakest part of the metric, so DPOY and All-Defensive carry more weight than their place in the league hierarchy would suggest. MVP and Finals MVP carry the most, because they describe the player the trade actually delivered.

AwardBonusRationale
MVP+5.0Carried the league. Captures dominance the box score understates.
Finals MVP+3.0Best player on the biggest stage. The most trade-relevant award we have.
DPOY+2.5Primary correction for the weakest part of WS.
All-NBA 1st Team+2.0Top five.
ROY+1.5Immediate impact. Relevant for graded picks.
All-NBA 2nd Team+1.2Top ten.
Sixth Man+0.8A role WS handles, but the award marks the player the league agreed on.
All-NBA 3rd Team+0.7Top fifteen.
MIP+0.5A breakout.
All-Defensive Team+0.5Defensive credit beyond DPOY.
All-Star+0.3Half popularity, half merit. Repeated selections matter more than the first.
All-Rookie Team+0.2Minor signal.

Awards are subjective, but they capture a league consensus about a player’s season.


WHY WIN SHARES

We tested every public alternative.

  • PER: Overweights volume scoring. The field has moved past it.
  • VORP: Correlates with WS at about 0.85, but does not factor in team success, essential to evaluating the success of a trade.
  • BPM: Per-possession rate stat. Does not factor in team success.
  • EPM, RAPTOR, LEBRON, DARKO: Proprietary, retired, or only available since 2014.

Win Shares is the only public metric that goes back to the merger and ties production to team outcomes. Both of those mattered.


DATA SOURCES

All from Basketball Reference. Stats count only after the trade, on the acquiring team.

  • Regular season: 23,500+ player-seasons (1977–present)
  • Playoffs: 9,100+ player-seasons
  • Championships: 49 verified champions
  • Accolades: 2,500+ awards
  • Trades: 1,935 (1976–present)
  • Salary contracts: 15,370 (1984–2031, 2,102 unique players)

EDGE CASES

Recent trades have fewer seasons banked. Their grades will move.
Sign-and-trades are flagged. The destination was the player’s choice.
Unresolved picks score zero until the player enters the league.
Three-team trades are scored independently per team. Facilitators usually grade poorly.