The NBA draft lottery is the league's way of determining the draft order and disincentivizing second-half tanking. The lottery gives each of the 14 non-playoff teams a chance to land one of the top three picks in the draft.
Although the top three picks of each draft are up for grabs via the lottery, the remaining order is determined by record, worst to best. The league's worst team isn't guaranteed a top-three spot in the draft, but has the best chance to land the first overall pick and will receive the fourth overall selection at worst.
The first three picks are determined by a draw of ping-pong balls numbered 1 through 14. Four balls are drawn, resulting in a total of 1,001 possible outcomes. 1,000 of those outcomes are assigned to the 14-non playoff teams -- for instance, if balls numbered 4, 7, 8, and 13 were chosen, that combination would belong to one of the 14 lottery teams. The 1,001st combination remains unassigned, and a re-draw would occur if it were ever selected.
The team whose combination is drawn first receives the number one overall pick, and the process is repeated to determine picks two and three. The 14 teams involved in the draft lottery are all assigned a different number of combinations, as follows (worst to best):
If two lottery teams finish the season with identical records, each team receives an equal chance at a top-three pick by averaging the total amount of outcomes for their two positions. For instance, if two teams tie for the league's ninth-worst record, each club would receive 14 combinations and a 1.4% chance at the first overall pick -- an average of the 17 and 11 combinations that the ninth- and tenth-worst teams receive.
If the average amount of combinations for two positions isn't a whole number, a coin flip determines which team receives the extra combination. For instance, if two clubs tied for the league's worst record, the team that wins the coin flip would receive 225 of 1,000 chances at the first overall pick, while the loser would receive 224. The coin flip also determines which team will draft higher in the event that neither club earns a top-three pick.
The table below displays the odds for each lottery team, rounded to one decimal place. For our purposes, the first seed is the NBA's worst team. Click to enlarge:
Note: This is a Hoops Rumors Glossary entry. Our glossary posts will explain specific rules relating to trades, free agency, or other aspects of the NBA's Collective Bargaining Agreement.