Leagues that assign incoming players by reverse order of finish create a direct reward for losing. The draft lottery exists to weaken that reward, and its design is a continuing negotiation with the same incentive.
The underlying incentive is structural
A team with no realistic prospect of success in a given season improves its future by acquiring a highly rated young player, and the draft is the main route to one.
If picks are ordered strictly by record, the worst team receives the best prospect, so every additional defeat late in a season is worth something.
The incentive is strongest where the difference between the first and fifth selection is large, which happens whenever a draft contains one clearly exceptional player.
A lottery breaks the direct link
Assigning weighted probabilities rather than fixed positions means the worst record improves the chance of the first pick without guaranteeing it.
Because the outcome is random, a team that loses deliberately may still finish outside the top selections, which makes the strategy expensive and uncertain.
The weighting is the design decision. Steep weighting preserves much of the incentive, while flat weighting reduces it and also reduces the help given to genuinely weak teams.
Flattening the odds spreads the risk
Giving the several worst teams identical or near-identical chances removes the benefit of finishing last rather than third from last.
That eliminates the most visible form of tanking, in which teams compete downwards over the final weeks of a season.
It does not remove the broader strategy, since a team can still choose a multi-year rebuild and accept several poor seasons in sequence.
Rebuilding is legitimate and hard to police
Resting veterans, trading experienced players for future picks and giving minutes to young players all serve development as well as losing.
A league cannot easily distinguish a team developing prospects from one avoiding victories, because the observable actions are identical.
Enforcement therefore targets extreme conduct rather than intent, which limits what any rule can achieve against a determined organisation.
Other levers matter more than the lottery
Limits on how many future picks a team may trade away prevent an organisation from mortgaging several seasons at once.
Revenue arrangements that reward attendance and competitiveness attach a financial cost to sustained failure that the lottery alone does not impose.
The lottery is consequently one component of a broader system, and leagues adjust it periodically because the incentive it addresses never disappears.
