The Formula for the Donovan Index determines the rate at which teams, and by extension cities, win championships. Using the Philadelphia 76ers as an example, our equation would be:
Let's make our example concrete: The 76ers have won the NBA title twice, in 1967 and 1983. The two championships are not equal, however. In 1967, the NBA had 10 teams; in 1983, it had 23. We call this discrepancy the "Riordan Factor". More credit is given for winning when more teams are competing. We thus award the 76ers 10 points for their first championship and 23 for their second. We determine their index score by adding 10 to 23 and dividing the sum by 48 seasons:
It thus follows that an average score is 1.00. In a ten-team league, a team should win once every ten years. Ten teams divided by ten seasons equals one. The 76ers score a 0.69; they don't win titles at an average rate. The city of Philadelphia scores a 0.74. It's that simple.
