Originally Posted by robthered

Both. Unpredictable - not that it matters because, I think, according to the latest edition here's how it breaks down -

He wouldn't trust his left foot so he'd use his right because it gives him more variety in positioning the ball. As we all know left footed pens are easier to predict.

But wait a minute - maybe he'd use his left because, as we all know, being able to predict the direction of the penalty has no relation to successfully scoring it.