At his best, and most confident, he shows the winger the sideline. It's a gamble, but he has the tools to smother his man or recover. I think Ben Arfa will have to work his way inside alot, off-the-ball.
For sure, when he gets himself in the right position, he's strong and difficult to get round. His problem is that he can lose concentration, get out of position, and then he struggles to recover.
His defending has improved, but to me, he's always looked more comfortable going forward.
He's a very very good defender - but is prone to the odd lapse in concentration. Flatters to deceive going forward for me.