07-13-2020, 09:47 AM

@Remi

Do you know who organised the most recent Renju olympiads? I'm still trying to find clear, formal, and tight definitions somewhere of exactly which forks the first player is allowed to create, and which ones not, and hoping such an event would have 100% tight rules described. Online I usually find mostly example situations of "this is allowed, this isn't", but not so many 100% complete definitions.

From what I understand so far, forks of two open threes are not allowed, two closed (or open) fours are not allowed, but one open three and one closed four is allowed... but then the definitions of "closed" and "open" can also be a bit confusing. Intuitively I would expect a line of three to be closed if and only if it is capped by opposing pieces or board edges on both sides of the three pieces (with one of the three being a "virtual" piece-to-be-placed). But the first image on http://www.renju.net/study/advanced.php describes Z as being allowed because the diagonal three it makes is a closed three. So, it seems that "closed" is defined in terms of the full line of five, rather than just the three (so really it's more like a "closed three-out-of-five").

Do you know who organised the most recent Renju olympiads? I'm still trying to find clear, formal, and tight definitions somewhere of exactly which forks the first player is allowed to create, and which ones not, and hoping such an event would have 100% tight rules described. Online I usually find mostly example situations of "this is allowed, this isn't", but not so many 100% complete definitions.

From what I understand so far, forks of two open threes are not allowed, two closed (or open) fours are not allowed, but one open three and one closed four is allowed... but then the definitions of "closed" and "open" can also be a bit confusing. Intuitively I would expect a line of three to be closed if and only if it is capped by opposing pieces or board edges on both sides of the three pieces (with one of the three being a "virtual" piece-to-be-placed). But the first image on http://www.renju.net/study/advanced.php describes Z as being allowed because the diagonal three it makes is a closed three. So, it seems that "closed" is defined in terms of the full line of five, rather than just the three (so really it's more like a "closed three-out-of-five").