Power Rankings using only Win/Loss
Posted: Mon Aug 04, 2014 9:46 am
Not an entirely new idea, but I've developed a power ranking where only wins and losses count. I'm adjusting for strength of opponent, location and back-to-backs etc.
Instead of using point differential I'm simply scoring each game as 1 or 0 (win/loss)
I'm using linear regression, which is probably far from perfect for this type of problem, but should still lead to decent results
Here are the '14 regular season ratingsThis needs to be interpreted the following way: The Spurs (with a rating of 21) vs the Heat (12) would have been estimated to have a 50+21-12 = 59% chance of winning on neutral ground. Home teams win ~60% of their games. Thus, the Spurs would have been estimated to have a 60+21-12 = 69% chance of winning at home, and a 49% chance of winning in Miami.
The 76ers vs the Spurs would have a 60-27-21 = 12% chance of winning at home, and a 40-27-21 = -8% chance of winning at the Spurs... that's linear regression for ya
Here's team specific homecourt advantage using this method
... effect of rest(*) small sample size
and the 10 top/bottom teams since '02
I'm strongly assuming that this type of power ranking is inferior to most power rankings that use point differential, but it would be interesting to see how a mix of this and a point differential based power ranking would perform
Instead of using point differential I'm simply scoring each game as 1 or 0 (win/loss)
I'm using linear regression, which is probably far from perfect for this type of problem, but should still lead to decent results
Here are the '14 regular season ratings
Code: Select all
╔══════════════════════════╦════════════╗
║ Team ║ Rating*100 ║
╠══════════════════════════╬════════════╣
║ San Antonio Spurs ║ 21 ║
║ Los Angeles Clippers ║ 19 ║
║ Oklahoma City Thunder ║ 17.4 ║
║ Indiana Pacers ║ 16.2 ║
║ Portland Trail Blazers ║ 15.4 ║
║ Houston Rockets ║ 13.9 ║
║ Golden State Warriors ║ 13 ║
║ Miami Heat ║ 12 ║
║ Memphis Grizzlies ║ 11.3 ║
║ Phoenix Suns ║ 7.1 ║
║ Dallas Mavericks ║ 6.9 ║
║ Chicago Bulls ║ 5.4 ║
║ Toronto Raptors ║ 5.2 ║
║ Washington Wizards ║ 3 ║
║ Charlotte Bobcats ║ 2.4 ║
║ Brooklyn Nets ║ 0.5 ║
║ Minnesota Timberwolves ║ -0.4 ║
║ Denver Nuggets ║ -1.1 ║
║ Atlanta Hawks ║ -2 ║
║ New Orleans Pelicans ║ -4.5 ║
║ New York Knicks ║ -5.9 ║
║ Cleveland Cavaliers ║ -8.9 ║
║ Sacramento Kings ║ -10.3 ║
║ Utah Jazz ║ -12.5 ║
║ Los Angeles Lakers ║ -13.4 ║
║ Detroit Pistons ║ -15.3 ║
║ Boston Celtics ║ -20.3 ║
║ Orlando Magic ║ -20.8 ║
║ Milwaukee Bucks ║ -27.1 ║
║ Philadelphia 76ers ║ -27.2 ║
╚══════════════════════════╩════════════╝The 76ers vs the Spurs would have a 60-27-21 = 12% chance of winning at home, and a 40-27-21 = -8% chance of winning at the Spurs... that's linear regression for ya
Here's team specific homecourt advantage using this method
Code: Select all
╔═════════════════════════════════════╦═══════════╗
║ Team ║ Extra HCA ║
╠═════════════════════════════════════╬═══════════╣
║ Denver Nuggets ║ 6.4 ║
║ Utah Jazz ║ 6.3 ║
║ Atlanta Hawks ║ 5.3 ║
║ Charlotte Bobcats ║ 4.7 ║
║ Indiana Pacers ║ 4.5 ║
║ Golden State Warriors ║ 4.2 ║
║ New Orleans Pelicans ║ 4 ║
║ Milwaukee Bucks ║ 3.9 ║
║ Washington Wizards ║ 3.8 ║
║ Los Angeles Clippers ║ 3.7 ║
║ Sacramento Kings ║ 3.4 ║
║ Cleveland Cavaliers ║ 3 ║
║ New Orleans/Oklahoma City Hornets ║ 2.6 ║
║ Portland Trail Blazers ║ 2.2 ║
║ Memphis Grizzlies ║ 1.5 ║
║ New Jersey Nets ║ 1.3 ║
║ Chicago Bulls ║ 0.6 ║
║ New York Knicks ║ -0.2 ║
║ Orlando Magic ║ -0.3 ║
║ Toronto Raptors ║ -0.8 ║
║ Minnesota Timberwolves ║ -1.1 ║
║ Los Angeles Lakers ║ -1.2 ║
║ Miami Heat ║ -1.4 ║
║ New Orleans Hornets ║ -2.1 ║
║ Detroit Pistons ║ -2.2 ║
║ Houston Rockets ║ -2.5 ║
║ Brooklyn Nets ║ -2.7 ║
║ Phoenix Suns ║ -3.1 ║
║ Seattle SuperSonics ║ -3.4 ║
║ Boston Celtics ║ -4.2 ║
║ Philadelphia 76ers ║ -4.5 ║
║ San Antonio Spurs ║ -5.1 ║
║ Dallas Mavericks ║ -5.2 ║
║ Oklahoma City Thunder ║ -5.5 ║
╚═════════════════════════════════════╩═══════════╝Code: Select all
╔══════╦════╦═══════════════╦═══════════════╦═════════════════════╗
║ Rest ║ OT ║ last location ║ this location ║ effect for awayteam ║
╠══════╬════╬═══════════════╬═══════════════╬═════════════════════╣
║ 1d ║ ║ away ║ away ║ 4.5 ║
║ 1d ║ ║ home ║ away ║ 3.8 ║
║ b2b ║ ║ away ║ away ║ -1.2 ║
║ b2b ║ OT ║ home ║ away ║ -1.3 ║
║ b2b ║ ║ home ║ away ║ -2.3 ║
║ b2b ║ OT ║ away ║ away ║ -5.1 ║
╚══════╩════╩═══════════════╩═══════════════╩═════════════════════╝
╔══════╦════╦═══════════════╦═══════════════╦═════════════════════╗
║ Rest ║ OT ║ last location ║ this location ║ effect for hometeam ║
╠══════╬════╬═══════════════╬═══════════════╬═════════════════════╣
║ 1d ║ ║ home ║ home ║ 5.1 ║
║ 1d ║ ║ away ║ home ║ 4.3 ║
║ b2b ║ ║ home ║ home ║ 1.6 ║
║ b2b ║ ║ away ║ home ║ -0.4 ║
║ b2b ║ OT ║ home ║ home ║ -7* ║
║ b2b ║ OT ║ away ║ home ║ -9.2 ║
╚══════╩════╩═══════════════╩═══════════════╩═════════════════════╝
╔══════╦════════╗
║ Rest ║ Effect ║
╠══════╬════════╣
║ 2d ║ 3.9 ║
║ 3d ║ 3 ║
╚══════╩════════╝
╔══════╦═══════════════════╗
║ ║ Additional Effect ║
╠══════╬═══════════════════╣
║ 4in5 ║ -2.4 ║
║ 3in4 ║ 1.1 ║
╚══════╩═══════════════════╝and the 10 top/bottom teams since '02
Code: Select all
╔═════════════════════════╦══════╦════════╗
║ Team ║ Year ║ Rating ║
╠═════════════════════════╬══════╬════════╣
║ Cleveland Cavaliers ║ 2009 ║ 27.5 ║
║ Dallas Mavericks ║ 2007 ║ 24.9 ║
║ Miami Heat ║ 2013 ║ 24.1 ║
║ Los Angeles Lakers ║ 2009 ║ 24 ║
║ Sacramento Kings ║ 2002 ║ 23.1 ║
║ Boston Celtics ║ 2008 ║ 22.9 ║
║ Detroit Pistons ║ 2006 ║ 22 ║
║ Cleveland Cavaliers ║ 2010 ║ 21.5 ║
║ Indiana Pacers ║ 2004 ║ 21.3 ║
║ Sacramento Kings ║ 2003 ║ 21.2 ║
║ … ║ ║ ║
║ New Orleans Hornets ║ 2005 ║ -24.2 ║
║ Cleveland Cavaliers ║ 2003 ║ -24.8 ║
║ Minnesota Timberwolves ║ 2011 ║ -25 ║
║ Milwaukee Bucks ║ 2014 ║ -27.1 ║
║ Philadelphia 76ers ║ 2014 ║ -27.2 ║
║ Atlanta Hawks ║ 2005 ║ -27.6 ║
║ Minnesota Timberwolves ║ 2010 ║ -27.7 ║
║ Miami Heat ║ 2008 ║ -28.5 ║
║ New Jersey Nets ║ 2010 ║ -30.4 ║
║ Charlotte Bobcats ║ 2012 ║ -33.1 ║
╚═════════════════════════╩══════╩════════╝