x + 1 system with up and down by y positions ....... usually, the x rounds is under swiss pairing system to get a ranking list. From the critical last one round, need to decide on the number of positions for up and down before : -- (1) up and down by maximum 1 position with : -- (coming 2010 Group A likely method) 1 vs 2 3 vs 4 5 vs 6 7 vs 8 ... (2) up and down by maximum 2 positions with : -- 1 vs 4 2 vs 3 5 vs 8 6 vs 7 ... (3) up and down by maximum 4 positions with : -- 1 vs 8 2 vs 7 3 vs 6 4 vs 5 ... 2009 3rd “芳庄旅游杯”越南象棋公开赛 used up and down by maximum 4 positions for positons 5 to 12 with (9 + 1) system : -- 5 vs 12 6 vs 11 7 vs 10 8 vs 9 You may read below : -- http://v15.huasing.org/bbs.php?B=123_11366782