The weighted draft lottery system the NBA uses to determine the top three draft selections has been in effect since 1990. While some changes have been made as more teams have come into the league, the general process has remained consistent.
Explaining how the NBA Draft lottery works
Ping-pong balls are selected from a machine in order to create four-digit combinations that have been assigned to each of the 14 teams in the lottery.
With 14 non-playoff teams participating in the lottery, 14 ping-pong balls numbered 1-14 are placed in a machine. The balls are mixed for 20 seconds before the first one is drawn. The remaining balls are then mixed for 10 seconds before the second one is drawn. This process continues until four balls have been drawn to create a four-digit combination to determine the No. 1 pick.
There are 1,001 total combinations, with one of those combinations thrown out and the other 1,000 distributed among the teams. The worst team in the league, which in this year’s case is the Philadelphia 76ers, gets 250 combinations and a 25 percent chance of winning the lottery. The odds get worse for each subsequent team.
The team with the best record in the lottery only gets five combinations, and that team this year is the Chicago Bulls. If two teams finish the season with the same record, each tied team gets the average of the total number of combinations for the draft positions they own. If the resulting average isn’t an integer, there’s a coin flip for the extra combination.
Here are the combinations and odds for this year’s lottery (via NBA.com):
After the No. 1 pick is determined, the same process is repeated for the second and third picks. Once that’s complete, the rest of the draft order goes in reverse order in terms of win-loss record.
The drawing isn’t shown to the public, which naturally leads to some questions about the lottery being rigged. However, the NBA has several measures in place to ensure no rigging occurs.
There’s a representative from the accounting firm Ernst & Young that oversees the actual drawing of the ping-pong balls, which is done in a separate room before the television broadcast. In addition to that person, there are other NBA officials, reporters, a machine operator, a timekeeper and representatives from each of the 14 lottery teams present.
Furthermore, electronic devices aren’t allowed to be used until the top pick is revealed on the broadcast. With the large number of people involved and the lockdown that takes place, rigging the lottery is just about impossible.
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