Rating System

Standard Rating
Blitz Rating
Duplicate Problem Rating Adjustment

The Chess Tempo rating system for tactics and endgames is based on the Glicko Rating System. Problems and Users are both given ratings and the user and problem rating are updated in a manner similar to the updates made after two players have played a game against each other. Generally, if you get a problem correct, the problem rating goes down , and your own rating goes up, and the opposite will occur if you get a problem wrong.

Standard Rating

The rating adjustment for standard mode tactics is the same as that outlined above , correct problems will give you a full 1-0 result, with you gaining points, and the problem losing points. Problems you get wrong will give a 0-1 result, with you losing rating points, and the problem gaining rating points.

Time is not part of the standard rating adjustment.

Blitz Rating

Unlike standard ratings, blitz ratings do use the time taken as part of the rating adjustment. This means if you take too long to solve a problem, you may lose rating points, even if you get the problem correct. Usually chess results come in three varieties, 1-0, 0-1 or 0.5-0.5, however the blitz rating system extends this to have values other than 0,1 and 0.5 as results, so for example a 0.25-0.75 result is possible, and when this result was fed into the Glicko rating system it would produce a rating adjustment that was worse than a draw, but better than a complete loss. The blitz rating system adjusts results in this way to account for time taken during the problem.

When you solve a blitz problem, you are competing against the average solve time of all users who got that problem correct. If you solve the problem faster than 1 standard deviation from the average solve time, then you get a solving bonus and instead of a 1-0 result, you are given the equivalent of a 1.25-0 result. If you solve slower than this, but faster than the average time, then you receive a full 1-0 result. If however you solve the problem less than the average time, then you receive a result proportionate to how much slower you took compared to the average. So for example if you took 20 seconds, and the average was 10 seconds you will receive a 0.5-0.5 result. As your solve time increases, your result will approach zero, for example if you take 40 seconds and the average was 10 seconds, then you will receive a 0.25-0.75 result.

Incorrect problems in blitz mode get a standard 0-1 result, where you lose rating points, and the problem gains them in the same manner as a normal loss. Note that blitz problems can gain points when you get a problem correct, as they receive 1 minus whatever value you receive as a result (with a minimum of 0), so as shown above if you receive a 0.25 result, your opponent will receive 0.75.

Note

To discourage guessing, and incremental solving, blitz problems also take account of time taken after the first move and ads an extra penalty for time taken after the first move. Essentially time taken after the first move is counted twice when accounting for total time taken. So a solve time of 10 seconds where 5 of those seconds were on the moves after the first, the total time used to calculate your rating adjustment would be 15 seconds (10 seconds + 5 seconds).

Duplicate Problem Rating Adjustment

To help reduce the impact on the rating system of users seeing problems multiple times, a reduction in the reward for successful attempts on problems that have been seen before has been implemented.

Note

Duplicate reward reduction now only applies to the top 1-3% of users in each rating type. This prevents the top 10 lists from being a list of users with the best memory for past problems, rather than the people with the strongest problem solving skills, but still allows lower rating users who are not getting large memory benefits from past attempts to get full reward for problems.

The current reductions are:

  • 1st Repeat - 70% of full credit

  • 2nd Repeat - 55% of full credit

  • 3rd Repeat - 45% of full credit

  • 4th Repeat - 35% of full credit

  • 5th Repeat - 25% of full credit

  • 6th and subsequent Repeats - 15% of full credit

There are also time decay adjustments made if the user has not seen the problem for a long time. So problems not seen for least 6 months receive a minimum of 45% of full credit, irrespective of how many times they were solved in the past. Similarly, problems not seen for a year are given 75% of full credit, no matter how many times they had been seen previously.