IPST (Internet puzzle solvers test) by Riad Khanmagomedov at the Diogen site. ~12 puzzles in the style of World Puzzle Championship.
Description of the tournament:
The objective is to solve 6 grids as quickly as possible. The tournament is designed as a relay, so you need to solve the grids in the following order:
1. consecutive sudoku
2. Chaos Sudoku ( = irregular sudoku = jigsaw sudoku)
3. sudoku X ( = sudoku diagonal)
4. arrow sudoku
5. killer sudoku
6. toroidal sudoku
You can download puzzles rules here.
Each of these grids is in a pdf file protected by a password. You can download them here. The procedure below explains in detail how you go about it.
There are two forms, one for starting the tournament and the other to finish. They are here.
The tournament runs from Wednesday 6th April 22h (GMT) to Wednesday 13th April 22h (GMT).