The majority of people here are retarded. An epic game of hot potato? It's to psychologically prepare them to act accordingly should they encounter a real life situation where a grenade gets tossed in their direction. Not only will they act calmly and with ruthless efficiency, they will know exactly how much time do they to toss the grenade back, or just duck for cover should the time constraints not allow it. Not panicking and running around like a bunch headless chickens, destroying their formation.