Basic Ranking Calculations

Doubles and Singles rankings are calculated using similar techniques. The basic difference is, in doubles the partners rankings are initially averaged then the calculation takes place like a singles match. Certain other adjustments are made which are based on the individual rankings of each player and the uniqueness of the game.

First the Players’ names are read from an unranked matches list.

The match ranking difference for each player is computed based on the match played by using the following formula:

Match Ranking Difference = Total Match Game Difference / Range factor / Number of Sets

The Range Factor determines the numeric value of a player's ranking. A Range Factor of 25 results in a ranking value range that looks similar the to USTA NTRP rating numbers.

SIMPLIFIED EXAMPLE:

Assume we have 2 "Veteran" players with the same number of total games recorded.

Player 1 beats Player 2 by set scores of 6-4, 6-3

The total match game difference is 12 - 7 = 5

The Match Ranking Difference is 5/25/2 = .100

A .100 difference means that for this match, the players' played as though their

Ranking values were different by .100 (say, 4.0 and 3.9).

If the players' current rankings are actually .100 apart (the "predicted difference"), there is NO

change in either of the player’s ranking as a result of the match.

But if the set scores were 6-1, 6-1 the calculations would be:

12 - 2 = 10 (the match game difference)

10/ 24 / 2 = .200 (the actual ranking difference)

.200 - .100 = .100 (the predicted ranking difference)

The software splits ½ the difference between the 2 players

The 4.000 player goes up .025

The 3.900 player goes down .025

The old ranks were: 4.000 3.900

Match adjustment: +.025 -. 025

The new ranks now are: 4,025 3.875

Now if the set scores were 7 - 6, 7 - 6

The calculations would be:

14 - 12 = 2 (the match game difference)

2/ 25 / 2 = .04 (the actual ranking difference)

.04 - .100 = - .06 (the predicted ranking difference)

(Negative since the 4.0 did not win by what the program calculated.)

The software splits ½ the difference between the 2 players.

The 4.0 goes down .015

The 3.9 goes up .015

The old ranks were: 4.000 3.900

Match adjustment: - .015 +.015

The new ranks now are: 3.985 3.915