UKD and ELO are two different rating systems used to represent the relative playing strength of chess players. Although they serve similar purposes, they are not administered by the same organisation, calculated under identical rules or used within the same scope.
UKD is Turkey’s national chess rating administered by the Turkish Chess Federation. ELO is the international rating system administered by the World Chess Federation, FIDE. A player may have both ratings, but their UKD and ELO do not have to be equal.
This guide explains the difference between UKD and ELO, tournament eligibility, calculation principles and where each rating is used.
UKD vs ELO: the short answer
In simple terms:
- UKD is Turkey’s national rating system administered by the Turkish Chess Federation.
- ELO is an internationally recognised rating system administered by FIDE.
- The two ratings are updated through separate tournament reports and calculation procedures.
- A tournament may be eligible for UKD, ELO or both if it meets the relevant requirements.
- There is no fixed formula for converting UKD into ELO or ELO into UKD.
What is UKD?
UKD stands for “Ulusal Kuvvet Derecesi,” which can be translated as National Strength Rating. It represents the relative playing strength of chess players at the national level in Turkey and is administered by the Turkish Chess Federation.
A player’s UKD is established and updated through eligible games played in tournaments that meet the requirements for UKD calculation. Opponents’ UKD ratings, game results and the current TSF calculation procedure are taken into account.
For a more detailed explanation, read the guide How is UKD calculated?
What is ELO?
ELO is named after Arpad Elo, the physics professor and chess player who played an important role in developing the rating system. International chess ratings are now administered and published by FIDE.
FIDE maintains separate ratings for standard, rapid and blitz chess. A player’s standard ELO may therefore differ from their rapid or blitz rating.
ELO changes take into account the player’s current rating, the opponent’s rating, the actual score, the expected score and the applicable K-factor. You can find a detailed explanation in How is ELO calculated?
Main differences between UKD and ELO
1. They are administered by different organisations
UKD is administered by the Turkish Chess Federation. ELO is administered internationally by FIDE.
Rating calculations, publication of rating lists, objection procedures and tournament reporting requirements are therefore governed by the regulations of the relevant organisation.
2. They have different areas of validity
UKD is a national rating used primarily within Turkish chess activities. ELO is internationally recognised and applies to FIDE-rated tournaments organised through FIDE member federations.
A player in Turkey may have only a UKD, only a FIDE ELO or both ratings.
3. Not every tournament affects both ratings
A tournament being held in Turkey does not automatically mean that its results will be included in both UKD and ELO calculations. The event must meet the requirements of the relevant system, and its results must be reported correctly.
The tournament regulations should state whether the event is eligible for UKD, ELO or both. When this is unclear, players should check the tournament regulations and the organiser’s official information.
4. The calculation rules are independent
In both systems, a player’s result and the opponent’s rating are important. However, the tables, coefficients, rating-difference limits, initial-rating conditions and rounding procedures do not have to be identical.
FIDE ELO rules cannot be applied directly to UKD calculations, and UKD procedures cannot be used directly to calculate a FIDE rating.
5. Initial rating requirements are different
The first UKD of an unrated player is established according to the game, opponent and performance requirements in the current TSF procedure. An initial FIDE rating is determined under the current FIDE Rating Regulations.
Eligible games against rated opponents are important in both systems, but required game counts, rating floors and calculation methods may change over time. Players should always check the current official regulations.
6. The rating lists are published separately
UKD records are published through the relevant TSF information systems and lists. FIDE ratings are published in FIDE’s international rating database.
An update in one system does not automatically change the other rating. A player’s UKD may increase while their ELO remains unchanged, or the reverse may occur.
7. Their uses may differ
Tournament organisers may use UKD, ELO or both for pairings, categories and starting rankings, depending on the event regulations.
FIDE titles and international rating records are governed by FIDE regulations. UKD does not replace a FIDE rating or the requirements for international titles.
Can a player have both UKD and ELO?
Yes. A player may obtain both ratings by playing eligible games in tournaments that count for UKD and FIDE rating calculations.
If a tournament in Turkey is eligible for both systems, the player’s results may be evaluated separately for UKD and ELO. The resulting changes do not have to be the same.
Why can UKD and ELO ratings be different?
It is normal for a player’s UKD and ELO to be different. Some common reasons include:
- The same tournaments and games may not be included in both systems.
- The opponent pools and opponent ratings may be different.
- The calculation procedures and coefficients may differ.
- The player may have completed more games in one system.
- The ratings may be updated at different times.
- The initial ratings may have been established using different methods.
A difference between the two numbers does not, by itself, indicate a calculation error.
Can UKD be converted into ELO?
There is no official fixed formula that can accurately convert UKD into ELO or ELO into UKD. Subtracting a fixed number from UKD to estimate ELO is not a reliable method.
Although both systems aim to describe relative playing strength, they use different player pools, tournaments and calculation rules. A player receives an official FIDE rating only after eligible FIDE-rated games have been processed under the applicable regulations.
Which is more important: UKD or ELO?
The answer depends on the player’s goals.
- UKD is important if you want to follow your progress in national tournaments in Turkey.
- ELO is important if you want an internationally recognised rating and a record in the FIDE database.
- For players who regularly compete in tournaments, both ratings may be meaningful in different ways.
It can also be misleading to evaluate progress only through rating. Game quality, decision-making, time management and the reduction of recurring mistakes are also useful indicators.
Is an online chess rating the same as UKD or ELO?
Usually not. Ratings on Chess.com, Lichess and similar platforms apply only within the platform’s own player pool and calculation system.
An online rating does not have to match a player’s UKD or FIDE ELO. It cannot be converted directly into an official UKD or ELO rating.
How can you estimate UKD and ELO changes?
Instead of calculating rating changes manually after a tournament, you can use the free tools developed by Mehmet Altınok:
These tools provide estimates based on the information entered. Ratings become official only after the tournament reports have been processed and published by the relevant organisation.
Where can official ratings be checked?
UKD ratings and national tournament records should be checked through the Turkish Chess Federation’s official information systems. FIDE ratings should be checked in the FIDE rating database.
Frequently asked questions
Can UKD and ELO be the same?
They may occasionally appear equal or very close, but they are calculated under separate systems and do not have to match.
Does a player with an ELO automatically receive a UKD?
This should not be assumed in every case. The player’s status, tournament conditions and the current TSF procedure must be considered together.
Does a player with a UKD automatically receive an ELO?
No. A FIDE rating requires eligible FIDE-rated games to be reported and processed under the FIDE Rating Regulations.
Can UKD and ELO changes differ in the same tournament?
Yes. Even when the same games are included in both systems, the calculation procedures and player data may differ, producing different rating changes.
Which rating is used for tournament pairings?
This depends on the tournament regulations and pairing settings. Players should check the event documents to see which rating is used.
Conclusion
The main difference between UKD and ELO is that UKD is a national rating administered by the Turkish Chess Federation, while ELO is an international rating administered by FIDE. The two systems have separate calculation rules, eligible tournaments and published rating lists.
A player may have both ratings, but they should not be expected to match or change by the same amount. Rating calculators can provide post-tournament estimates, while the official TSF and FIDE records should be used for final results.
Accuracy note: UKD and FIDE rating regulations may change over time. Always check the current TSF procedures and the FIDE Rating Regulations for technical requirements involving game counts, rating limits, time controls and tournament eligibility.