for regular go-moku (which this is essentially the same) i have never played on a board bigger than 13x13. They use that at IYT...i have played approximately 200 games of that and 2 of them have filled up, both agaginst the same person (lol). 15x15 would certainly be big enough though imo!
(do skréše) Chce se tě zrovna valet rechlé špil, keré zaročeně skonči v pruběho dvó hodin? Vetvoř nabidko ke špilo a zadé tam Čas na špil: 0 dni 1 hodina, Extrovnica: 0 dni 0 hodin, Limit: 0 dni 1 hodina. (TeamBundy) (okázat šecke vechetávke)