Two fingers pointed downward means a line block on both attacks. So if they serve either player the blocker is going to cover the line attack and the back defender covers the cross court attack.

两根手指向下表示对两个对手球员的进攻都进行直线拦截。所以，如果他们每人负责一个对手球员，那么拦截者负责接直线球，而后卫负责接斜线球。