Racket Sport Rating Calculator

This is an illustrative 1–7 model for all sport selections. It does not calculate NTRP, DUPR, BWF, PSA or USATT ratings, convert official points, or predict a certified competition rating.

Choose a sport context, enter generic ratings from 1 to 7, and enter whole nonnegative wins and losses. The sport selector changes the context label only. Official points such as USATT 1500 are invalid on this scale and remain visible for correction.

E = 1/(1 + 10^((opponent − own) × 2)). A 0.5-point disadvantage gives E=1/11 (9.09%). K is 0.40 below 3, 0.32 below 4, 0.24 below 5 and 0.16 otherwise, measured in generic rating points per outcome. Raw change = K × (wins − games × E). These are illustrative parameters, not official Elo-400 rules.

Projected rating is capped to 1–7. Displayed change equals projected minus current, so the cap is already applied. From 6.9 against 6.9 with two wins, raw change is +0.16; projection is 7.00 and applied change +0.100.

With zero recorded games, observed win rate and rating change are unavailable. The expected-probability curve depends only on the entered generic ratings.