This is the tenth installment of the Fortnightly Topic Challenges Rerun described here and the fifty-first installment of the FTCs overall, with topics suggested and voted on here. This fortnight's topic is "Non-rectangular grids" (suggested by Bubbler) and will span from the 7th of March to the ...

This is the third question of my mini series on decentralised chess, or Swiss chess. In Swiss chess, the advantage in terms of mobility of a centrally placed piece over a piece in the corner is compensated for simply by opening up additional squares a marginalised piece has access to. This applie...

This is the fourth entry in my decentralised or "Swiss" chess mini series. See bottom for a recap of the modified rules of Swiss chess. Enough warm up! It is time for a proper Swiss chess problem: Task: Consider the Swiss KNN-K endgame: All pieces except for the two kings and two white knights h...

What is the next term in the sequence: 1, 1, 2, 3, 5, 8, 18, 34, 60, 120, 214, 394, 788 hints: #1