Update released on April, 20th, 2019
- Puzzles that were labeled "draw or win" have now been split into two separate tasks, "regain material", and "defend".
- The filter has been extended with the two new tasks.
- Winning puzzles can now be filtered further for "checkmate" and "material gain".
- Drawing puzzles can now be filtered further for "stalemate", "repetition", and "insufficient material".
- If you select a combination of filters with few or no matching puzzles, and you have solved all of them, you are returned to the filter with a warning message.
Update released on March, 10th, 2019
- Fixed a bug where some puzzles were published before they were completed.
Update released on January, 13th, 2019
Update released on January, 8th, 2019
Update released on October, 11th, 2018
- Fixed a bug with some stalemate puzzles.
Update released on October, 8th, 2018
Update released on August, 12th, 2018
- Fixed a bug where some positions were not correctly labeled with "there is a better move".
Update released on June, 16th, 2018
- In positions with a forced mate, allow alternate solutions if they are quicker. For example, capturing the Queen is now allowed as a solution in a position where the best move is a long complicated mate.
Update released on May, 5th, 2018
- Chess tournaments can now be featured on the daily puzzle.
- Fixed a bug where some puzzles without a solution were published in error.
Update released on April 13th, 2018
- Fixed a bug where "there is a better move" was shown for the best move, which made it impossible to solve some puzzles.
Update released on August 16th, 2017
- Homepage updated with dynamic lists of puzzles.
Update released on August 10th, 2017
- When promoting, you can now select the promotion piece, instead of auto-queen. Puzzles that require an under-promotion can now be solved correctly.
- Puzzles that always end with perpetual check, move repetition, stalemate, or insufficient mating material, are now labeled as "to draw", instead of "to draw or win". Puzzles that end with an equal or slightly better position are still labeled as "to draw or win" as before.
- The browser engine was upgraded to Stockfish.js 8.
- Engine evaluations are now always displayed from White's point of view.
- Engine evaulations are now displayed with an added symbol ("+-", etc.)
- The solution variation now always starts with the last move before the puzzle. This enables correctly displaying the solution variation if the puzzle is at the end of a game.
- The solution variation is now preselected. This means that if you use the replay buttons, the solution will be replayed, which is a better experience, especially on mobile.
- On mobile, the buttons and engine are now displayed before the notation, which makes the engine usable on many mobile devices without scrolling.
- Puzzles where the result depends on the 50 moves rule are no longer generated.
- Puzzles do no longer end if a winning condition is reached, but the next move is still forced.
- Fixed a bug that caused the generation of some puzzles that had no solution.
- Fixed several bugs with the generation of reply moves.
- Improved detection of reply moves that would lose material.
- Improved generation of reply moves in table base positions.
- All puzzles were recalculated to fix these issues in existing puzzles. Some puzzles are no longer available.