Green was up the hill from tee box, and when I hit the ball, I knew it was left of the pin. Couldn't see the bottom of pin. When I got to the green, I saw my ball mark and a ball near my mark. I bent down to fix the ball mark, and noticed that the ball wasn't mine. One of my playing partners suggested that I look in the hole. I said, "C'mon" walked over, and there it was, sitting in the bottom of the hole.