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

Example: Robert def Miguel 6-1,6-0

Robert's ranking before match was 4.203 (740 total games in last 12 months) Robert's ranking after match: 4.228 ; his ranking change: + .024

Miguel's ranking before match was 4.146 (he played a total of 316 total games in last 12 months) his ranking after match: 4.09 change: - .057

Match Ranking Difference = Total Match Game Difference / Range factor / Number of Sets 11 / 25 = ..4583 / 2 = .229

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

SINGLES RANKINGS

The Player's (& Opponent's) name is read from an unranked singles matches query record followed by retrieval of the PlayerRoster data by matching the Player's (& Opponent's) name.

A test is then made for an assigned ranking of ZERO.

For Singles, a ranking cannot be computed if both player and opponent have a ZERO ranking. If one player is ranked and the other is not then the unranked player is provisionally assigned the same ranking as his opponent. If neither player has a ranking the operation is terminated until at least one of the players can be assigned a ranking value.

Calculations proceed if at least one player has a ranking. The ranking types are recalculated since they may change as a result of the additional games played in the current match being processed.

The Predicted Ranking Difference is then computed and is based on the original rankings of the player and the opponent.

PredictedRankingDiff(Player) = OriginalRanking(Player) - OriginalRanking(Opponent) 4.203 - 4.146 = .057

PredictedRankingDiff(Opponent) = OriginalRanking(Opponent) - OriginalRanking(Player)

The next computation is the Net Ranking Difference between the predicted difference and the real difference based on match results.

NetRankingDiff(Player) = MatchRankingDiff(Player) - PredictRankingDiff(Player) .229 - .057 = .172

NetRankingDiff(Opponent) = MatchRankingDiff(Opponent) - PredictRankingDiff(Opponent)

Allocation Ratios are determined as the next step. The Allocation Ratio is the distribution of the ranking difference that the player and his opponent will absorb. This involves each individual since the ratio is based on ranking types and the results of the match played (i.e.; winner or loser). The ratio will be either 0, -or- .5, -or- will be based on a formula involving ratios of total games played (original total + new match total) by the player and the opponent. If both player and opponent had essentially the same number of total games on record the allocation will be "50/50", meaning each player gets half of the total difference between the predicted rating difference and the actual difference based on match results.

AllocRatio(Player) = TotalGames(Opponent) / (TotalGames(Player) + TotalGames(Opponent))

AllocRatio(Opponent) = TotalGames(Player) / (TotalGames(Player) + TotalGames(Opponent))

The ranking change for each player is now calculated. The maximum possible change using a RangeFactor of 25 is +/-.12 and that would be the result of a 6-0 match score (8-0 = +/- .16) if the maximum allocation ratio of .5 is calculated. If both player and opponent are within the same total game range (i.e.; the same Ranking Type), the ranking change is based on the following:

RankingChange(Player) = NetRankingDiff(Player) * AllocRatio(Player) .172 - .45 = .057

RankingChange(Opponent) = NetRankingDiff(Opponent) * AllocRatio(Opponent)

These are the new singles rankings.

NewRanking(Player) = OrigRanking(Player) + RankingChange(Player) 4.146 - .057 = 4.09