The Elo ranking lists – explanation and method of calculation home


The NTTB rating system is based on the method developed by the American physicist and chess player 👉Árpád Élő. After analysing match data over many years, the rating points table has been adapted to Dutch table tennis.

1. GENERAL PRINCIPLES
1.1. Every player has a certain rating. The winner of a match gains points. Points are deducted from the loser of a match. The number of points the winner gains and the loser loses depends on the difference in rating between the two players.
1.2. The number of points added to or subtracted from the total is determined by the rating points table. The table 👉Expected results is used when the winner's rating is higher than the loser's. The table 👉Unexpected results is used when the winner's rating is lower than the loser's.
1.3. No points are awarded for a win against a player without a rating. If a player with a rating loses to a player without a rating, 8 points are deducted from the loser's rating.

2. WEIGHTING OF RESULTS
2.1. Depending on the league or the tournament, the points added for a win are multiplied by a given weighting factor. The more important the tournament, the higher the weighting factor.
2.2. There are six multiplication factors. The lowest is 0.5 and the others are respectively:
- for league play and team tournaments (R1) the weighting factor is 1,
- points are multiplied by 1.25 (R2),
- points are multiplied by 1.5 (R3),
- points are multiplied by 1.75 (R4),
- points are multiplied by 2 (R5).
2.3. The multiplication factor on a loss is applied to the R1 column and is:
- 0.5 for R0,
- 0.90 for the national junior leagues,
- 0.75 for the regional junior leagues,
- 1 in all other cases.
2.4. All values in the rating points table are rounded to whole numbers (👉see the tables).

3. NEW PLAYERS
3.1. All players who held a strength number (sterktegetal) based on their league results up to 1 January 2010 were assigned a so-called INITIAL RATING. The initial rating for 2010 equals the strength number used at that time: (strength number+100)*3. The initial rating of players added after 1 January 2010 is calculated as follows:
3.2. A player enters the ranking list as soon as they have won at least one match against a player who already had a rating at the time that match was played. They first receive a PROVISIONAL RATING. With one match won, the provisional rating equals the rating of the ranked player. With two or more matches won, it equals the average rating of the two best players they have beaten, calculated on the basis of the results available at that moment. A win over a player who had no rating at the time of that match does not count, not even if that player goes on to obtain a rating later in the same half of the season.
3.3. Provisional ratings are recalculated for every new NTTB ranking list until a player in the senior category has achieved at least 5 wins against players who already have a rating, in a minimum of 10 matches regardless of whether the opponents have a rating. In the junior category a minimum of 3 matches won is required, regardless of whether the opponents already have a ranking or not. If a junior player without a ranking wins 3 matches against players who likewise have no ranking, they receive an initial ranking of 100 points. From that moment on the player receives a definitive INITIAL RATING.
For the ranking lists, players in the age categories O11 up to and including O19-1 are regarded as juniors. A player in age category O19-2 or older is regarded as a senior, since from that age category a senior licence can be obtained without special permission.
3.4. From the moment the initial rating becomes definitive, the initial rating equals the average rating of the two best players the player has beaten. In general this number of points will be lower than the rating of the best player they have beaten.
3.5. If a player has no registered matches for 4 years, an entirely new initial rating is calculated.

4. LAPSED PLAYERS
4.1. Players who have played no matches counting towards the ranking list for one year (two consecutive halves of the league season) are no longer listed on the published ranking lists. These players do, however, keep their rating points for 4 years, until the moment they become active again. During the period in which they are not listed on the ranking list, these players can still be entered on seeding lists for tournaments on the basis of their rating points.

EXPECTED RESULTS
(Higher ranked player wins)
Weight: R0 R1 R2 R3 R4 R5
Difference in
points		 0.5 1 1.25 1.5 1.75 2
≥300 0 0 1 1 1 1
270-299 1 1 1 2 2 2
240-269 1 2 3 3 4 4
210-239 1 2 3 3 4 4
180-209 2 3 4 5 5 6
150-179 2 3 4 5 5 6
120-149 2 4 5 6 7 8
90-119 3 5 6 8 9 10
60-89 3 6 8 9 11 12
30-59 4 7 9 11 12 14
15-29 4 7 9 11 12 14
0-14 4 8 10 12 14 16

UNEXPECTED RESULTS
(Lower ranked player wins)
Weight: R0 R1 R2 R3 R4 R5
Difference in
points		 0.5 1 1.25 1.5 1.75 2
0-14 4 8 10 12 14 16
15-29 5 9 11 14 16 18
30-59 5 10 13 15 18 20
60-89 7 13 16 20 23 26
90-119 9 17 21 26 30 34
120-149 11 21 26 32 37 42
150-179 13 26 33 39 46 52
180-209 16 32 40 48 56 64
210-239 20 39 49 59 68 78
240-269 23 46 58 69 81 92
270-299 28 55 69 83 96 110
≥300 32 63 79 95 110 126
The winner of a match gains points according to the weighting factor of the league or tournament concerned. Points are deducted from losers according to factor 1 (the second column), with the exception of:
4.2. Meaning of the markers next to the players' names:
* the player has achieved no results counting towards the ranking list during the current half of the league season
** the player has achieved no results counting towards the ranking list during the last two years
n this is the first ranking list on which the player appears (after 2 wins)
r the player's initial rating has been recalculated on this ranking list compared with the previous one (the player's second best win has changed)
f this is the ranking list on which the initial rating has become definitive points (at least 5 wins in 10 matches; or 3 wins for juniors)

5. APPLICATION IN EVENTS
5.1. Tournament results are only included in the Elo ranking list when they have been registered with the NTTB and are listed in the events calendar.
Tournament results must be sent within 1 week of the last match to the e-mail address NTTB-Seniorenlicenties and must be supplied in an approved digital format. Information about the suitable formats can be 👉found here.
5.2. The "Invitation" document must be published before the tournament and must also remain available afterwards. (It is possible to place an "Invitation" on the ranking list page. In that case send the document to the following e-mail address: NTTB-Seniorenlicenties).
5.3. Weights of tournaments:
R0 ➡ All registered events not named under R1 to R5 and/or not played, or only partly played, according to NTTB regulations.
R1 ➡ NTTB league and other team tournaments.
R2 ➡ Tournaments run by a tournament leader (TL) holding licence 2 or higher. The tournament must be listed in the events calendar.
R3 ➡ Tournaments run by a tournament leader (TL) holding licence 3 or higher and for which an association representative has been appointed. The tournament must be listed in the events calendar.
R4 ➡ National multi-group events (meerkampen) and national ranking tournaments organised by the NTTB, run by a tournament leader (TL) holding licence 3 or higher and for which an association representative has been appointed.
R5 ➡ Dutch Championships and the NTTB CUP.

6. DOUBLES PAIRS RANKING LIST
6.1. The Elo doubles pairs ranking list is in force as of 1 July 2026.
6.2. The initial rating of a doubles pair is calculated on the basis of their Elo ratings, taking the average of both players' ratings at the moment they first play together. If only one player of the pair has an Elo rating, that rating is used for the pair.
6.3. The number of points added to or subtracted from the total is determined by the rating points table, as for individual players. The table 👉Expected results is used when the winners' rating is higher than the losers'. The table 👉Unexpected results is used when the winners' rating is lower than the losers'.
6.4. The Elo rating of a doubles pair never lapses, not even when a pair has not played together for a long time.

7. PARA RANKING LIST
7.1. The Elo para ranking list is in force as of 1 July 2022.
7.2. The para ranking list contains only players who are registered as para table tennis players in the NTTB membership administration and have taken part in a tournament registered in the Elo system.
7.3. The para ranking list is calculated in the same way as the general NTTB ranking list. The points tables used for the calculation are identical as well. The weighting factor of the events that count towards the para ranking list is as follows:
R0 ➡ all other local and small-scale tournaments
R2 ➡ Recreational tournaments, factor 20 (national participation possible)
R3 ➡ Para ranking tournaments, factor 30 (factor to be determined by the CPT*)
R4 ➡ Para ranking tournaments, factor 40 (factor to be determined by the CPT*)
R5 ➡ NK Para and NJK Para
*Depending on the size of the tournament, the location, the participants and the type of organisation.
7.4. The initial ranking is calculated as follows:
  1. If, at the moment of their first match in a qualifying para event, a player already had a rating on the general NTTB ranking list, the rating from the general NTTB ranking list is used as the initial para rating,
  2. If, at the moment of their first match in a qualifying para event, a para player has no rating yet, the initial para rating is the average of the first two matches won against players who already had a para rating at the time those matches were played,
  3. If a para player has not played against players with a para rating, that player receives an initial para rating of 100 ranking points after three wins against players without a para rating (as also applies to junior players on the general NTTB ranking list)
7.5. The para ranking list contains only players who are members of the NTTB. The rating is calculated on the basis of the results of earlier tournaments, on the assumption that the player was a member of the NTTB at the time those events were played.
7.6. As of 1 July 2022 the results of para events are no longer included in the general NTTB ranking list, but only in the para ranking list. Results of para players in para events that were included in the general NTTB ranking list before 1 July 2022 do remain on the general NTTB ranking list. If para players take part in general NTTB events, those results are processed in the general NTTB ranking list, but not in the para ranking list.
7.7. On 1 July and 1 January the para classes are recalculated automatically. The para Elo ratings for obtaining a para class are as follows:
Class Standing Wheelchair
1 1000 850
2 850 450
3 650 200
4 450 0
5 200
6 0
7.8. In sliding table tennis (schuiftafeltennis) the number of matches is limited, which means the Elo algorithm cannot be applied. The ranking list for sliding table tennis is therefore calculated as the weighted average of the matches played over the past five years.
The algorithm works as follows:
rating = sum of the weighted averages over the past 5 years
weighted average = (sum of the number of matches played in the past 5 years / number of years in that period in which matches were played) * (number of wins / number of matches played in a given year) * weight of that year
weight of that year = all registered matches in one year divided by 10

ver. 01-09-2026