Oakland Raiders : biggest year-to-year improvement/decline

Based on regular season win percentage:

                            Change in 
                              win %
Improvement: 1981 -> 1982     0.451   (0.438 -> 0.889)
Decline:     2002 -> 2003    -0.438   (0.688 -> 0.250)
Last Year:   2018 -> 2019     0.188   (0.250 -> 0.438)