NBA Draft Lottery Explanation

The NBA Lottery is an exciting time for team wishing for luck to bounce their way. Being held during the fourth week of May, the lottery consists of the teams that do not qualify for the playoffs vying for the best draft picks.

In order to determine the winner, fourteen ping pong balls are numbered one through fourteen. They are put into a standard lottery machine and four balls are selected. The order of the balls is irreverent. Therefore, there are a total of 1,001 possible combinations, but one is discarded. This means that there are 1,000 possible outcomes. Before the draft, each team gets a designated amount of the 1,000 outcomes based on record. Here is a list of the amount of combinations each teams gets.

The team with the worst record gets 250 combinations.
The team with the second worst record gets 199 combinations.
The team with the third worst record gets 156 combinations.
The team with the fourth worst record gets 119 combinations.
The team with the fifth worst record gets 88 combinations.
The team with the sixth worst record gets 63 combinations.
The team with the seventh worst record gets 43 combinations.
The team with the eighth worst record gets 28 combinations.
The team with the ninth worst record gets 17 combinations.
The team with the tenth worst record gets 11 combinations.
The team with the eleventh worst record gets 8 combinations.
The team with the twelfth worst record gets 7 combinations.
The team with the thirteenth worst record gets 6 combinations.
The team with the fourteenth worst record gets 5 combinations.

In order to calculate the odds of getting the first pick, multiple the amount of calculations by .1%. Therefore, a team with 250 combinations has a 25% chance at the top pick, while the team with 5 combinations only has a .5% chance to get the first pick.

In order to find out what possible picks a team may get, you must know their record and where it stands. All teams have a chance for the top three picks. Then, add two to the team's position (if a team has the twelfth worst record, add two to twelve to get fourteen) and the range of these numbers are the highest and lowest of the picks not in the top three. Therefore, the team in twelfth place can only get a draft pick that is first, second, third, twelfth, thirteenth, and fourteenth. Using this method, the team with the worst record is guaranteed a top four pick.

In the event of a tie, the amount of lottery picks for the two slots are combined and averaged. If it is not an even number, a coin flip decides the last combination. For example, Minnesota and Portland tied for the sixth worst record, so the sixth place and seventh place combinations were combined and each team got 53 combinations. A coin flip gave Portland the last combination.

Wikipedia, NBA Draft Lottery