#1168 1985 · National Basketball Association (David Stern, Norm Sonju) · Professional sports league
The NBA killed calculated tanking by replacing a predictable coin-flip with a lottery
问题
A predictable coin-flip for the top draft pick let front offices calculate exactly what losing games was worth
背景
In the 1983-84 season the Houston Rockets, sitting a respectable 24-36, lost 17 of their final 22 games, a collapse widely read around the league as a bid to finish with the league's worst record and win a coin flip for the rights to draft Hakeem Olajuwon. Under the rule then in place, the two non-playoff teams with the worst record in each conference met in a coin flip for the top two picks, so the value of losing was not just real, it was arithmetic: a team could work out in advance exactly how many additional losses moved it into the flip.
Dallas Mavericks general manager Norm Sonju, outraged that a team could simply engineer its way into a fifty-fifty shot at a franchise player, pushed the league to act. Banning tanking directly was unenforceable — nobody could prove a coach was resting a healthy player to lose — so the fix had to remove the payoff from the calculation instead of trying to police the behavior that chased it.
换别人会怎么做
The league could have tried to punish tanking directly — fining teams for resting healthy players, investigating suspicious late-season collapses — but intent is nearly impossible to prove and coaches always have a game-management excuse. It also could have just given the top pick to the single worst team, which only sharpens the incentive to be historically bad.
他们看到了什么
Stern didn't catch teams tanking — he made tanking uncalculable. A coin flip is a priced bet you can buy by losing enough; a lottery turns losing into an unpriced maybe you can't optimize toward.
那一手
Commissioner David Stern replaced the coin flip with a lottery: beginning in 1985, all seven teams that missed the playoffs were given equal odds, drawn from envelopes in a rotating drum, at the first seven picks — so losing more games no longer bought better odds than losing just enough to miss the playoffs.
为什么管用
The old system rewarded losing with a discrete, known probability that got better as record got worse — a front office could model the payoff of every additional loss. Spreading equal odds across all seven non-playoff teams severed that link: the team that lost the most got the same shot as the team that missed the playoffs by two games, so there was no marginal loss worth engineering. The mechanism didn't stop teams wanting the pick, it stopped losing from being the reliable way to buy it.
值了多少
The Knicks won the first lottery for Ewing on odds no better than the next-worst team; Stern called it the end of 'win by losing.'
什么时候会失灵
Equal odds only removes the incentive to lose a lot; it does nothing to stop the incentive to lose at all, since any lottery ticket beats none — which is why the league had to add weighting in 1990 once teams realized just missing the playoffs was worse than missing them badly. It also assumes the participants can't manipulate the draw itself; conspiracy theories about the 1985 draw (a frozen or bent envelope) dogged the league for years, showing how much the mechanism depends on trusted randomness.
后来呢
Equal odds solved calculability but created a new complaint — a team desperate enough to lose 65 games got the same shot as one that missed the playoffs by two — so in 1990 the league introduced weighted odds tied to record, then in 1994 replaced envelopes with ping-pong-ball combinations after Orlando won the top pick with a single ball out of sixty-six in 1993. The lottery, in its various weighted forms, became the standard the NHL, MLS and other leagues copied whenever a coin flip or strict worst-record-first rule made losing too calculable to resist.
资料来源
- [1]A history of the NBA Draft Lottery and its changes over timeNBA.com, 2024nba.com
- [2]Complete history of the NBA Draft Lottery: Four decades of tanking, the efforts to stop it and what's nextCBS Sports, 2024cbssports.com