This is the sixth installment of the Fortnightly Topic Challenges Rerun described here and the fortieth installment of the FTCs overall, with topics suggested and voted on here. This fortnight's topic is "Retrograde Analysis" (suggested by Riley) and will span from the 15th of October to the 28th of October. During this period, we will compile the list of relevant questions and post it as an answer to this question.

In the meantime, please go and propose and vote on future challenges!

Everyone have fun, and happy puzzling!

Link to other Fortnightly Topic Challenges.

Examples of previous puzzles may be found by clicking on the tag, and the full tag wiki entry is here.

The original suggestion here provides a list of games that may work well with the challenge, but there are many more, and puzzlers are always encouraged to show creativity by finding interesting puzzles outside of expectation.


1 Answer 1


List of all questions published as part of the Fortnightly Topic Challenge #40:

The highest-voted and the most viewed of these is Mate in 0 moves by JGibbers, with a score of 82 and approximately 12600 views at the end of the fortnight.

  • $\begingroup$ What does the "colorful glass circle" puzzle has to do with chess? $\endgroup$
    – vsz
    Commented Oct 22, 2018 at 21:58
  • 4
    $\begingroup$ @vsz This fortnight's topic is not "Chess" but "Retrograde Analysis". But the question remain: What does the "colorful glass circle" puzzle has to do with Retrograde Analysis ? $\endgroup$
    – Evargalo
    Commented Oct 23, 2018 at 8:25

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .