A wiry, bespectacled man with a mop of grey hair is engaged in a boxing match against what looks like a pile of red bricks. He is backed into a corner; his eyes are popping out of his head with exertion. ‘Unfortunately, I forgot to plan the picture so I would win the boxing match and consequently I’m getting beat up pretty bad,’ writes the American artist Peter Saul in the notes accompanying his latest exhibition at Michael Werner Gallery in London.