Wei Collection, Upper Volume
Radical: Bamboo (zhú)
Sai
Kangxi stroke count: 19
Page 901, Entry 48
Guangyun (Broad Rhymes), Jiyun (Collection of Rhymes), Yunhui (Collection of Rhymes), Zhengyun (Correct Rhymes): Pronounced sai.
Shuowen (Explaining Characters): A method of blocking in board games is called sai.
Commentary on the Biography of Wuqiu Shouwang in the Book of Former Han (Qianhan shu): The method for the ge-wu game is to block the white piece by moving five spaces; if it reaches five spaces and cannot move, it is called ge-wu.
Commentary: Shigu says: This is the same as the game of sai today.
Commentary on the Biography of Liang Ji in the Book of Later Han (Houhan shu): Bao Hong wrote the Classic of Sai.
Also, Yunhui (Collection of Rhymes): Generally written as sai. Zhuangzi mentions bo-sai.
Also, Leipian (Categorized Compilation): Weaving bamboo and wood together to block water and catch fish.