This is a page I'm adding to collect some of the aesthetically pleasing, even beautiful Sudoku puzzles that come my way. Some will be just normal Sudokus with interesting clue distributions, some will have special properties outside the strategy lists that would place them there.
Nine empty units. Could be wrong, but I can't believe there can be more than nine.
Discovered by Klaus Brenner
This first set has been created by the prolific compiler Klaus Brenner
Minimal at 24 Clues with a 5x5 blank space in the center
25 Clues, minimal "Anchor“
23 Clues, minimal "Battlement“
23 Clues, minimal "Vase“
24 Clues, minimal "2x3x3 mirrored by diagonal“
24 Clues, minimal "2 squeezed naughts mirrored by diagonal"