The NBA Draft lottery is designed to promote competitive balance by awarding better draft positions to weaker teams, but it creates incentives to deliberately lose, a practice known as tanking. We propose a draft mechanism that is simultaneously practical, incentive-compatible, and advantages weaker teams. The Carry-Over Lottery Allocation (COLA) Draft Mechanism represents a paradigm shift in evaluating team quality, replacing a single season's standings with playoff outcomes over multiple years. COLA uses a draft lottery where every non-playoff team receives the same number of lottery tickets, removing incentives to lose additional games after elimination. Lottery tickets that do not win a top draft pick carry over to future lotteries, while playoff success or winning a top pick diminishes a team's accumulated tickets. Over time, COLA rewards teams with poor long-term performance and less prior draft assistance. By retaining the lottery format, COLA preserves transparency and fan engagement. Real-world implementation challenges are addressed to demonstrate feasibility, including transitioning from the current system, handling traded draft picks, and accommodating draft classes of varying strength. The most significant challenge occurs in years with exceptionally strong draft classes, where teams may prefer missing the playoffs in order to gain lottery access, violating a foundational assumption: that teams prefer playoff success to lottery participation. We provide a solution to this problem, employing a truth-elicitation mechanism to identify such years and expand lottery eligibility to include as many playoff teams as necessary to preserve anti-tanking incentives.

翻译：NBA选秀抽签机制旨在通过授予较弱球队更好的选秀顺位来促进竞争平衡，但这会诱发故意输球的动机，即所谓的"摆烂"行为。我们提出一种兼具实用性、激励相容性且有利于弱势球队的选秀机制。结转彩票分配选秀机制代表了评估球队质量范式的转变，以多年季后赛表现取代单赛季战绩排名。该机制采用所有非季后赛球队获得相同数量彩票的抽签方案，消除了球队在确定淘汰后继续输球的动机。未赢得高顺位选秀权的彩票将结转至未来抽签，而季后赛成功或赢得高顺位选秀权则会减少球队累积的彩票数量。长期来看，该机制奖励长期表现不佳且先前获得较少选秀援助的球队。通过保留抽签形式，该机制维持了透明度与球迷参与度。研究针对实际实施挑战提出解决方案以证明可行性，包括现行体系过渡、交易选秀权处理以及不同强度选秀年份的适配。最严峻的挑战出现在选秀人才异常突出的年份，此时球队可能更倾向于放弃季后赛以获取抽签资格，这违背了"球队更重视季后赛成功而非抽签参与"的基本假设。我们通过采用真实偏好揭示机制来识别此类特殊年份，并将抽签资格扩展至必要数量的季后赛球队，从而维持反摆烂激励机制。