1947-1965: Regional roundup
To take advantage of the regional popularity of college stars, the NBA used territorial picks in its first 18 years, which gave a team the option of forfeiting its first-round pick before the draft to select any player within the immediate geographical area. Territorial picks included: Wilt Chamberlain, Jerry Lucas, Bob Ferry, Tom Heinsohn, Bill Bradley, Gail Goodrich, Dave DeBusschere and Walt Hazzard.
1966-84: Pick a side, any side
The NBA adopted a coin-flip policy between the last-place finishers in each of its two divisions for the top pick. The rest of the field were assigned picks based on won-lost records. In 19 years, tails was the winner 12 times.
1985-1986: Ping-Pong Ball Era
After Houston finished last in the Western Conference in 1983 and '84, landed two No. 1 picks and selected 7-footers Ralph Sampson and Hakeem Olajuwon, the draft underwent a complete makeover and the first lottery was created. Non-playoff teams were given an equal chance of landing the top pick, and the remaining teams picked in inverse order for the first round only.
1987-1989: Lottery 2.0
The first lottery created more headaches than it solved and needed tweaking. The changes determined who would be given the top-three picks and ensured that the team with the worst record would select no lower than fourth. Also in 1989, the lottery was reduced to just two rounds. In the early years, the draft lasted two days and went on until the league ran out of prospects.
1990-1993: The Poor get Richer
A weighted system was introduced in 1990, which included 11 non-playoff teams. The team with the worst record received 11 chances (out of 66) at getting the top pick, the second-worst team got 10 chances, the third-worst got nine and so forth.
1994-1995: The Orlando Rule
The Magic finished the 1992-93 season with a .500 record and narrowly missed the playoffs. They had a one chance out of 66 to win the top pick, but parlayed their odds into the No. 1 overall spot and selected Penny Hardaway. In November of 1993, the NBA increased the odds of teams with the worst record winning one of the top three picks (from 16.7 percent to 25 percent) and decreased the odds of teams with better records.
1996-2003: 13-team lottery
With the addition of expansion teams Toronto and Vancouver, non-playoff teams grew to 13 teams, which slightly decreased the chances of teams with better records of winning the lottery.
2004-present: 14-team lottery
The Charlotte Bobcats joined the league in 2004, and the odds of eight lottery teams diminished. Under the current system, 14 ping-pong balls numbered 1 to 14 are placed in a drum. There are 1,001 possible combinations when four balls are drawn, and prior to the lottery 1,000 combinations are assigned to non-playoff teams based on their records. Four balls are drawn to determine a four-digit combination and the team with that combination receives the No. 1 pick. The process is repeated to determine the No. 2 and No. 3 picks.