Xi Dach tao nen suc hut rieng nho nhung man so diem cang thang va kha nang doi bai thanh thang chi trong mot luot bai. Nguoi choi can quan sat the bai, tinh toan diem so va lua chon thoi diem boc them hoac dung lai that hop ly. He thong duoc toi uu de thao tac muot ma, ket qua ro rang va bao ve thong tin thanh vien trong suot qua trinh tham gia. Doi ngu ho tro luon san sang dong hanh de moi ban dau tro nen tron ven hon.
