Not really... just shield as soon as you see rocks coming on the top left of the screen, and make sure you aren't in the top left, alternatively take cover in the bottom right, they don't quite come all the way... Better still, you can taunt the cowboy over to into the path of the rocks, and if you shield in time the rocks move on before he unflattens, so you can hit him for six when he does... Only way to beat a hard computer unarmed, I think. Well, maybe you can on UC.