Philadelphia 76ers biggest year-to-year improvement/decline

Based on regular season win percentage:

                            Change in 
                              win %
Improvement: 2017 -> 2018     0.293   (0.341 -> 0.634)
Decline:     1950 -> 1951    -0.312   (0.797 -> 0.485)
Last Year:   2025 -> 2026     0.256   (0.293 -> 0.549)