Calcudoku puzzle forum

Today the site has been up for 17 years

Subscribers will already have seen today's special puzzle:

Thank you for all that you have done, Patrick.

It will be twelve years in April for me.

eclipsegirl wrote: ↑Tue Feb 10, 2026 4:00 pm Thank you for all that you have done, Patrick.

I second that. No, wait, I 17th that

Thanks for the puzzle, Patrick.

I finally got around to solving it last night. But I’m slightly puzzled by the rankings.

The score for solving it appears in the overall rankings and the 7 day book rankings. And I got an achievement award for having solved a book puzzle in 2026. But it is not included in the all time book rankings and the puzzle is not listed on the book history page.

So it seems to be treated as a special puzzle rather than a book puzzle, or maybe a hybrid between the two?

Hm yes that does sound inconsistent, will check..

edit: pretty sure it's because special puzzles use the same mechanism, with a "book code".

edit 2: special puzzles (list at https://www.calcudoku.org/ops/special_history/en) no longer count towards the "book achievements"

edit 3: points for the special puzzles are no longer added to the "book total" (/ book rankings). To correct this for past submissions will require a bit of work