Sigurbjörn Lárusson's blog

Musings of a network engineer

Shake up the NBA playoffs

It's early January, and I've been thinking about how the NBA post-season system is broken. This is certainly not the first time I've thought about this, but it seems to be happening earlier in the year every season.

The three main reasons why I think the current system is broken are the following

  • There is a discrepancy in the quality of teams in the Eastern and Western conference, this makes it easier for the teams in the East to make the Playoffs
  • Teams in each conference play a majority of their games (52 out of 82 games, or 63.5%) against teams in their own conference, making that discrepancy bigger
  • Owing to the fact that the teams play more games against their own conference, teams play an unequal amount of games between themselves, teams in the same division meet 4 times, teams in the same conference but not in the same division meet 3 or 4 times, and teams in separate conferences meet 2 times.
There have been a number of suggestions on how to solve this, each viewpoint has some merit and I'm going to go over the most common suggestions and then wrap up with a discussion on how I would most like to see it.

Wait it out

Every year we hear that the Eastern conference is bound to get stronger than it was last year. In this article from BBall Breakdown they go over the history since the current Eastern/Western conference and Divisional Split and compare the win/loss records of teams in the conferences since those changes were made.

In this millennium, the Eastern Conference has had a better record once, in the 2008-2009 season. This is not to say that there haven't been strong teams in the Eastern conference during that time (including the Pistons, Shaq/Wade Heat, Big-3 Heat, and the Big-3 Celtics), although from the 2000-2001 season and up until now, the West has claimed 10 titles against 5 titles to the East teams. Out of the 10 West victories, there are 2 sweeps (4-0) and 3 gentleman's sweeps (4-1).

There is little to support the argument that this will go away on its own, in fact since the 2000-2001 season, the winning percentage of Eastern teams is 42.1% and last season it was only 36.9%. Again, this is not to say that there aren't strong teams in the Eastern Conference, the top 3-4 teams in the East have traditionally been strong, the fact that a few select teams in the East have a winning percentage against teams from the Western Conference doesn't really change the overall balance of the rest of the conference.

I've compiled the current (as of January 9th) 2014-2015 standings against conferences and calculated the current standings against the conferences for each team in this table

Eastern Conference
TeamWinsLossesWin PctConf WinsConf LossesOther WinsOther LossesWin Pct against EastWin Pct against West
Atlanta27877,1% 17 6 10 2 73,9%83,3%
Chicago251169,4% 16 5 9 6 76,2%60,0%
Toronto241168,6% 15 6 9 5 71,4%64,3%
Washington241168,6% 16 6 8 5 72,7%61,5%
Cleveland191752,8% 15 9 4 8 62,5%33,3%
Milwaukee191851,4% 13 11 6 7 54,2%46,2%
Brooklyn161945,7% 11 13 5 6 45,8%45,5%
Miami152141,7% 11 12 4 9 47,8%30,8%
Indiana142337,8% 8 10 6 13 44,4%31,6%
Charlotte142436,8% 10 11 4 13 47,6%23,5%
Boston122136,4% 9 13 3 8 40,9%27,3%
Detroit122334,3% 6 11 6 12 35,3%33,3%
Orlando132534,2% 9 18 4 7 33,3%36,4%
Philadelphia52914,7% 4 14 1 15 22,2%6,3%
New York53412,8% 4 19 1 15 17,4%6,3%
Western Conference
TeamWinsLossesWin PctConf WinsConf LossesOther WinsOther LossesWin Pct against EastWin Pct against West
Golden State28584,8% 17 5 11 - 100,0%77,3%
Portland28877,8% 12 6 16 2 88,9%66,7%
Memphis251071,4% 16 5 9 5 64,3%76,2%
Dallas261170,3% 10 7 16 4 80,0%58,8%
Houston251169,4% 15 8 10 3 76,9%65,2%
LA Clippers241266,7% 13 6 11 6 64,7%68,4%
San Antonio211558,3% 12 13 9 2 81,8%48,0%
Phoenix221657,9% 10 10 12 6 66,7%50,0%
New Orleans171848,6% 13 11 4 7 36,4%54,2%
Oklahoma City171947,2% 9 14 8 5 61,5%39,1%
Denver162044,4% 9 11 7 9 43,8%45,0%
Sacramento152042,9% 12 13 3 7 30,0%48,0%
Utah132336,1% 6 12 7 11 38,9%33,3%
L.A. Lakers112530,6% 6 21 5 4 55,6%22,2%
Minnesota52914,7% 2 20 3 9 25,0%9,1%

The data clearly shows the difference between the conferences. 4 teams out of 16 in the East have a winning percentage against the West, half of them have a 33.3% or poorer record against teams in the Western Conference. 7 teams in the Eastern Conference have a below 40% total winning percentage, despite playing the majority of their games against their weaker Eastern Conference rivals.

In comparison, 10 teams in the West have a winning percentage against the East and only 2 of them have a 33.3% or poorer record against the Eastern Conference teams, and only 3 teams have a poorer than 40% total winning percentage, despite playing the majority of their games against the stronger Western Conference.

Statistically, this should eventually balance out, how long that would take however is anyone's guess, there's nothing in the data to suggest this is changing. We've heard talk recently that the top teams in the East are doing much better against the West. That does not seem to be the case, while the overall winning percentage in the East is 42.6% now, better than last year, the winning percentage against the Western Conference is at 36.8% which remains very poor.

Swap teams to balance the talent pool

Mark Cuban (and undoubtedly many others) have given some thought to moving teams from the Western conference into the Eastern conference and vice-versa in an attempt to balance the talent pools of the respective conferences.

In his suggestion, as reported on, he suggests moving the Texas teams (Spurs, Mavericks and Rockets) as well as the Pelicans from the Western conference out East, and moving the Bulls, Pacers, Bucks and Pistons to the Western conference instead.

Although this idea has merit at this point in time, there is no guarantee that those 4 teams will remain weak or strong for any amount of time, so even though this is undoubtedly a short-term fix (which would benefit the Dallas Mavericks which Cuban owns) there is no guarantee that this would fix things in the long term.

Top 16 teams make the Playoffs

This idea has merit although you'd have to somehow make up for the uneven number of games played between each team. I see three potential ways to solve that.

Calculate a power ratio for each team, and use that to seed them

If you want to keep the current scheduling and number of games, you'd have to come up with something other than the total Wins and Losses, since that is obviously biased in favour of the Eastern Conference teams currently. The simplest way of doing this is to simply add a correction factor. The way things are currently, the correction factor would lower the affect of a win against the Eastern Conference (making a win against the Eastern Conference worth less than 1 win) while a win against a Western Conference opponent would be worth 1 win exactly. If the balance of power was reversed, the factor would be applied to wins against the Western Conference. As I see it, there are at least 3 (and possibly many more, some far more complicated) ways to calculate the factor

  • A calculation of total win percentages in the conferences, (currently would be 42.6/51.3, giving a factor of .830)
  • A calculation of inter conference win percentages (currently would be 36.8/57.1, giving a factor of .644)
  • A calculation of inter conference win percentages and total win percentages (currently would be (42.6+36.8)/(51.3+57.1), giving a factor of .732)
None of them are completely fair (and never would be), I believe the last option might be the most reasonable. That would mean that each victory against the East is only worth .732 wins, if the Playoff cut would be made today. I've calculated the top 20 teams in the NBA based on a factor of .732 and they are listed in the table below
Top 20 overall teams based on a factored win percentage
TeamFactored Wins
Golden State (1)25.05
Portland (2)23.71
Memphis (3)22.59
Atlanta (4)22.44
Houston (5)22.32
Dallas (6)21.71
LA Clippers (7)21.05
Chicago (8)20.71
Toronto (9)19.98
Washington (10)19.71
Phoenix (11)18.78
San Antonio (12)18.59
New Orleans (13)15.93
Milwaukee (14)15.52
Cleveland (15)14.98
Oklahoma City (16)14.86

This list reads far more like a power ranking list, and probably isn't far off base. Changing the factor to .830 (the first calculation option) doesn't change the 16 teams, but does move the top East teams slightly up. Putting these 16 teams into the Playoffs (with the top 8 having home court advantage, just like the current system) would certainly make for some very interesting Playoff series.

Have the teams play an equal amount of games between them

The other way is to make the teams play an equal amount of games between each other, which would mean that a win was just a win. As I see it, seeing as there are 29 teams, and 82/29 is not an even number, there are two ways to do this

  • Have each team meet 3 times (3*29 games or 87 games) which is an increase of 5 games to the currently very long 82 game season. This would mean an unequal amount of home and away games, although you could alternate this every other year (and likewise the matches, if you had two home games and a road game against team X in one year, you would have two road games and a home game next year to balance it out)
  • Have each team meet 2 times, (2*29 games or 58 games), one home and one way, which is what the proponents of shortening the season are generally rooting for

I'm not against either proposal, although changing the number of games, would put a dent in comparing statistics between seasons with an unequal number of games played, probably more true if you were to shorten it to 58 games. If you shorten the season, by a whopping 24 games, you are skewing per game numbers (players get more rest, are able to play more minutes per game, upping their statistics, but less games are played so the total is lower). Perhaps it would finally put a rest to comparing players from different eras, but I doubt it.

Best 4 make the Playoffs, best 12 compete for 8 spots

The proposal I'm advocating is a mix of the best 16 and the current well known system with a wild card addition. In this proposal, the top 4 teams in the West and East would always make the Playoffs (and therefore all the division winners since a division winner is always ranked among the top 4 regardless of win percentage), 2 teams outside of the top 4 teams in the East and West would also have a reserved spot, regardless of conference. The remaining 6 spots would go to the victors in 6 best-of-3 series amongst the top 12 remaining teams (regardless of conference).

If this cut were made today, the following teams would move forward

10 safe teams
TeamWinsLossesWhy they're in
Golden State285Top 4 in Western conference
Atlanta288Top 4 in Eastern conference
Portland288Top 4 in Western conference
Memphis2510Top 4 in Western conference
Dallas2611Top 4 in Western conference
Chicago2511Top 4 in Eastern conference
Toronto2411Top 4 in Eastern conference
Washington2411Top 4 in Eastern conference
Houston2511Top 2 outside of the Top 4 East/West teams
L.A. Clippers2412Top 2 outside of the Top 4 East/West teams

The wild card best-of-3 series would be between the following 12 teams, (based on their Rank after the first 10 safe teams have been found)

Team 1 (Rank)Team 2 (Rank)
San Antonio (1)Charlotte (12)
Phoenix (2)Indiana (11)
Cleveland (3)Miami (10)
Milwaukee (4)Sacramento (9)
New Orleans (5)Denver (8)
Oklahoma City (6)Brooklyn (7)

The winning teams would advance to take one of the 6 remaining spots. Once all teams would have been established, they would get home court advantage and play each other based on their win percentage and face each other in 8 best-of-5 series. The top team would play the team with the 16th best record and so on. The remaining 8 teams from these 8 best-of-5 series would then move on to best-of-7 series, then we'd have 4 teams compete in a best-of-7, and finally the Finals in a best-of-7. The Finals could happen between two teams that would both be from the same conference (which seems reasonable and fair if the two strongest teams are in the West or in the East).

The pros as I see it

  • More teams make the Playoffs (22 out of the 30 teams, only the bottom 8 teams don't go in), possibly giving less incentive to tank
  • Top 4 teams from each conference and the best 2 of the rest get a sure spot, and get a break during the wild card round, giving them time to rest their players
  • Changing the second (first after wild card) round into a best-of-5 lessens the boredom of lopsided matches between very strong and very weak teams, giving way to the 3-0 sweep, it also makes the first and second round not much longer than the current first round
  • The top team is going against the 16th best team so it's very unlikely that a good team is wiped out in the first round, it's also very unlikely that it happen in the second round keeping the best teams in the Playoffs
  • Once the third round is reached the best 8 teams should remain and should make for exciting 7 game series
  • The best two teams will meet in the Finals

There are undoubtedly many flaws with this proposal (we still have an unbalanced schedule so the East teams play more games against other East teams and vice-versa, we also still have the divisional system in place and we'd have to do away with the Western and Eastern conference champions, at least in the manner in which it is done today) and probably many others, agree or disagree, or write about it somewhere, let me know