Biggest improvements from one season to the
next (based on regular season win percentage):
                                             Change in
       Franchise                               win %

  1 Boston Celtics            2007 -> 2008     0.512   (0.293 -> 0.805)
  2 San Antonio Spurs         1997 -> 1998     0.439   (0.244 -> 0.683)
  3 San Antonio Spurs         1989 -> 1990     0.427   (0.256 -> 0.683)
  4 Phoenix Suns              2004 -> 2005     0.402   (0.354 -> 0.756)
  5 Boston Celtics            1979 -> 1980     0.390   (0.354 -> 0.744)
  6 Milwaukee Bucks           1969 -> 1970     0.354   (0.329 -> 0.683)
  7 Miami Heat                2008 -> 2009     0.341   (0.183 -> 0.524)
  8 Oklahoma City Thunder     2009 -> 2010     0.330   (0.280 -> 0.610)
  8 Phoenix Suns              1988 -> 1989     0.330   (0.341 -> 0.671)
 10 Denver Nuggets            2003 -> 2004     0.317   (0.207 -> 0.524)
 10 New Jersey Nets           2001 -> 2002     0.317   (0.317 -> 0.634)
 12 Chicago Bulls             1995 -> 1996     0.305   (0.573 -> 0.878)
 13 Chicago Bulls             2004 -> 2005     0.293   (0.280 -> 0.573)
 13 Cleveland Cavaliers       1991 -> 1992     0.293   (0.402 -> 0.695)
 15 Phoenix Suns              1969 -> 1970     0.281   (0.195 -> 0.476)
 16 Dallas Mavericks          1994 -> 1995     0.280   (0.159 -> 0.439)
 16 Golden State Warriors     1988 -> 1989     0.280   (0.244 -> 0.524)
 18 Memphis Grizzlies         2003 -> 2004     0.269   (0.341 -> 0.610)
 19 Houston Rockets           1968 -> 1969     0.268   (0.183 -> 0.451)
 20 Toronto Raptors           1998 -> 1999     0.265   (0.195 -> 0.460)
 21 Boston Celtics            1997 -> 1998     0.256   (0.183 -> 0.439)
 21 Chicago Bulls             2010 -> 2011     0.256   (0.500 -> 0.756)
 21 Cleveland Cavaliers       2008 -> 2009     0.256   (0.549 -> 0.805)
 21 Los Angeles Clippers      1973 -> 1974     0.256   (0.256 -> 0.512)
 21 Los Angeles Lakers        1971 -> 1972     0.256   (0.585 -> 0.841)
 21 Washington Wizards        1968 -> 1969     0.256   (0.439 -> 0.695)

    Last season:
    Chicago Bulls             2010 -> 2011     0.256   (0.500 -> 0.756)
    Philadelphia 76ers        2010 -> 2011     0.171   (0.329 -> 0.500)
    New York Knickerbockers   2010 -> 2011     0.158   (0.354 -> 0.512)
    New Jersey Nets           2010 -> 2011     0.147   (0.146 -> 0.293)
    Miami Heat                2010 -> 2011     0.134   (0.573 -> 0.707)
    San Antonio Spurs         2010 -> 2011     0.134   (0.610 -> 0.744)
    Golden State Warriors     2010 -> 2011     0.122   (0.317 -> 0.439)
    New Orleans Hornets       2010 -> 2011     0.110   (0.451 -> 0.561)
    Boston Celtics            2010 -> 2011     0.073   (0.610 -> 0.683)
    Memphis Grizzlies         2010 -> 2011     0.073   (0.488 -> 0.561)
    Indiana Pacers            2010 -> 2011     0.061   (0.390 -> 0.451)
    Oklahoma City Thunder     2010 -> 2011     0.061   (0.610 -> 0.671)
    Detroit Pistons           2010 -> 2011     0.037   (0.329 -> 0.366)
    Los Angeles Clippers      2010 -> 2011     0.036   (0.354 -> 0.390)
    Dallas Mavericks          2010 -> 2011     0.024   (0.671 -> 0.695)
    Minnesota Timberwolves    2010 -> 2011     0.024   (0.183 -> 0.207)
    Houston Rockets           2010 -> 2011     0.012   (0.512 -> 0.524)