Lottery

The NBA draft lottery is an annual event held by the National Basketball Association (NBA), in which the teams who had missed the playoffs the previous year participate in a lottery process to determine the draft order in the NBA draft. In the NBA draft, the teams obtain the rights to amateur U.S. college basketball players and other eligible players, including international players. The lottery winner would get the first selection in the draft. A lottery pick denotes a draft pick whose position is determined through the lottery, while a non-playoff team involved in the process is often called a lottery team.

Only the top four picks are decided by the lottery, and are chosen from the 14 teams that do not make the playoffs. The team with the worst record, or the team that holds the draft rights of the team with the worst record, has the best chance to obtain a higher draft pick. After the top four positions are selected (from the lottery slotting system), the remainder of the first-round draft order is in inverse order of the win-loss record for the remaining teams, or the teams who originally held the lottery rights if they were traded. The lottery does not determine the draft order in the subsequent rounds of the draft.

The NBA changed the lottery odds (the bottom three teams will all have an equal 14% chance of winning the top pick) and increased the number of teams selected in the lottery from three to four.

The lottery is normally held during either the third or fourth week of May.

The pool of lottery contestants consists of the 14 teams who failed to qualify for that season’s playoffs. They are seeded in order from worst record to best, with each team’s seed determining the odds it will have of winning one of the top three draft picks.

The winners of the top three picks are determined by the following process, beginning with the first draft pick. Fourteen ping pong balls numbered 1–14 are placed in a standard lottery machine and four balls are randomly selected one at a time from the lot. The balls are placed in the machine for 20 seconds to randomize before the first ball is drawn. The remaining three balls are drawn after remixing for 10 seconds. Just as in most traditional lotteries, the order in which the numbers are drawn is immaterial; e.g., a drawing of 1–2–3–4 in that order is the same as 4–1–3–2.

There are a total of 1,001 possible combinations of four balls numbered 1 through 14. One such combination (balls 11-12-13-14 regardless of order) is deemed invalid and will be ignored if drawn. The remaining 1,000 combinations are distributed amongst the lottery contestants according to their seed’s assigned odds. For example, because each of the top 3 seeds has a 14% chance of winning the top pick, they are each assigned 140 of the 1,000 possible winning combinations.

The balls drawn in determining each of the first three picks are returned to the lottery machine and can be drawn again. However, a team generally cannot win multiple picks, so the drawing of a combination assigned to a team who has already won a pick will be ignored, and balls will be drawn again. The exception to this rule applies where the winner of the lottery pick acquired the pick via trade.

When a lottery team trades its first pick to another team, the recipient of the pick assumes the seed “earned” by the original owner of the pick, unless the terms of the trade provide otherwise. When a lottery team trades its first pick to another team that missed the playoffs, the recipient receives the seed of the team who traded it away as well as the seed determined by its own record (unless it also traded its first pick). This is the only situation in which a team can win multiple lottery picks. Trades are also the only way in which playoff teams can win a lottery pick.

The lottery is conducted with witnesses (from the accounting firm Ernst & Young) auditing the process to verify that it is conducted in accordance with the rules.

Since the number of lottery winners was increased from 3 to 4, with the remaining picks still assigned based on regular season record, a team can drop no more than four spots from its seeded position to its actual draft position.

The odds of each seed winning the first pick are:

1. 140 combinations, 14.0% chance of receiving the No. 1 pick;
2. 140 combinations, 14.0% chance;
3. 140 combinations, 14.0% chance;
4. 125 combinations, 12.5% chance;
5. 105 combinations, 10.5% chance;
6. 90 combinations, 9.0% chance;
7. 75 combinations, 7.5% chance;
8. 60 combinations, 6.0% chance;
9. 45 combinations, 4.5% chance;
10. 30 combinations, 3.0% chance;
11. 20 combinations, 2.0% chance;
12. 15 combinations, 1.5% chance;
13. 10 combinations, 1.0% chance;
14. 5 combinations, 0.5% chance.

In the event that teams finish with the same record, each tied team receives the average of the total number of combinations for the positions that they occupy. Should the average number not be an integer, a coin flip is then used to determine which team or teams receive the extra combination. The result of the coin flip is also used to determine who receives the earlier pick in the event that neither of the tied teams wins one of the first four picks via the lottery.

The drawing of the ping-pong balls is conducted in private, though observed by independent auditors and representatives from each team. The results are subsequently presented in a televised unveiling (presented as an hour-long special by ESPN), in which the order of the lottery is announced in reverse order, from the fourteenth selection to the first. Representatives from each lottery team are present at the lottery ceremony.