PRSR (Personal Record : Site Record) is a ratio. To keep it between 0% and 100%, we use SR / player's score for a particular track. The further the score from the SR, the smaller the ratio. This chart shows the average for ratios for all 64 NonSC-only charts.

PRSR scores reward consistency. A single weak score can negatively affect you in a big way! Your PRSR improves when you get a new PR... unless you already had the SR yourself. Your PRSR worsens when somebody else sets a new SR.

You need 64/64 scores to be shown. By default, the top 100 players are shown.