Los Angeles Lakers biggest year-to-year improvement/decline
based on regular season win percentage:

                            Change in 
                              win %
Improvement: 1971 -> 1972     0.256   (0.585 -> 0.841)
Decline:     2004 -> 2005    -0.268   (0.683 -> 0.415)
Last Year:   2007 -> 2008     0.183   (0.512 -> 0.695)