UKD (Ulusal Kuvvet Derecesi, or National Strength Rating) is Turkey’s national chess rating system. Administered by the Turkish Chess Federation (TSF), it does not award or deduct a fixed number of points for every win or loss. Opponents’ UKD ratings, expected scores and eligible games all influence the calculation.
This guide explains the basic logic of UKD calculation, the difference between UKD and FIDE Elo, and how you can estimate your rating change after a tournament.
What is UKD?
UKD stands for “Ulusal Kuvvet Derecesi,” which can be translated as National Strength Rating. It represents a player’s performance in Turkish chess tournaments that are eligible for national rating calculation.
A player’s UKD is not permanently fixed. It may increase or decrease after eligible events, depending on the player’s results, opponents’ ratings and the applicable calculation rules.
How is UKD calculated?
The basic calculation compares a player’s actual score with the score expected from the rating difference. A win counts as 1 point, a draw as 0.5 and a loss as 0. The expected score depends on the rating difference between the two players.
The simplified logic can be expressed as:
Rating change = K factor × (actual score − expected score)
Changes from all eligible games in the tournament are combined and applied to the current rating:
New UKD = Current UKD + total UKD change
The K factor and expected-score values are determined by the applicable procedure and its tables. A win therefore does not always add the same number of points, and a loss does not always deduct the same amount.
How does the opponent’s UKD affect the result?
The general logic is straightforward:
- A good result against a higher-rated opponent may exceed your expected score.
- Losing to a lower-rated opponent may fall below your expected score.
- When two players have similar ratings, their expected scores are also closer.
- A draw does not have the same effect in every pairing; the rating difference matters.
For this reason, counting wins alone is not enough to estimate a tournament’s UKD change.
How does an unrated player receive a first UKD?
A player who is not yet on the UKD list is not handled in exactly the same way as an already-rated player. The initial rating process considers tournament performance, eligible opponents and the minimum valid-game conditions defined by the procedure.
Because thresholds and administrative details may change, players seeking their first UKD should check the latest TSF calculation procedure and confirm that the tournament is eligible for UKD rating.
How to use the UKD calculator
Instead of calculating every round manually, you can use the UKD calculator developed by Mehmet Altınok.
To use the tool:
- Enter your current UKD rating.
- Add one row for each round you played.
- Enter your opponent’s UKD for every round.
- Select win, draw or loss.
- Review the estimated change for each round and the total result.
The tool also helps you evaluate several rounds together and store tournament entries in your browser.
Does the calculator show the official result?
No. The UKD calculator provides an estimate based on the information entered. The official rating is determined by the Turkish Chess Federation and confirmed in its published records.
Differences between the estimate and the official result may be caused by:
- An incorrect opponent rating or game result
- Including a game that was decided without being played
- A tournament or game not being eligible for UKD calculation
- The opponent’s rating status being handled differently
- Special rules, tables or rounding in the applicable procedure
The calculator is therefore best used for estimation and checking after a tournament.
Are UKD and Elo the same?
No. UKD and FIDE Elo serve similar purposes, but they are separate rating systems.
- UKD is Turkey’s national chess rating administered by the TSF.
- Elo is the international rating administered by FIDE.
- A player’s UKD and Elo ratings do not have to be equal.
- A tournament may be eligible for UKD, Elo or both, depending on its regulations.
FIDE Elo rules should therefore not automatically be treated as UKD rules.
When does a UKD calculation become official?
A value displayed by a calculator is only an estimate. The official record appears after tournament files have been reviewed, eligible results have been processed and the TSF has published the data. Check the federation’s official information system for your current rating and tournament reports.
Frequently asked questions
Is the UKD calculator free?
Mehmet Altınok’s web-based UKD calculation tool is free to use and requires no installation.
Can I calculate UKD on a phone?
Yes. The web-based tool can be opened in a modern mobile browser.
Why did my UKD increase less than expected?
Your opponent’s rating, your expected score, eligible games and the applicable procedure all affect the result. Looking only at the number of wins can be misleading.
Can I object to a UKD calculation?
If you believe an official tournament report or UKD record is incorrect, follow the TSF’s current announcement and objection procedure. An estimate produced by the calculator is not an official objection document.
Conclusion
UKD calculation is not a simple system that adds a fixed number of points for a win. A player’s current rating, opponents’ ratings, actual and expected scores, and eligible tournament records are considered together.
You can open the UKD calculator for a quick post-tournament estimate and use the TSF records for the official result.
Update note: UKD procedures may change. Always rely on the latest TSF regulations and information system for technical details and official results.