Flash fiction challenge, 99 words, Slave to the game.

Through the fence I could see the warriors on their ponies. Bare-chested in check trousers, their tattoos, symbols of their bravery in battle. Each had a wooden stave which they swung around their heads as they passed a tall tree in the field, from which hung a large sack. The one who hit and made the sack fall was acclaimed the winner to loud cheers. The sack was then dragged off to be refilled. I was hoping this would be a long time for, being a prisoner I was due to be the next one sewn into the sack.