Protection for Ramirez. He wants someone the pitcher will "fear," or respect, batting behind Ramirez to give him some protection. Therefore, against lefties - with whom Kosuke may have some problems - he will put Soriano in the 5 spot to provide better protection for Ramirez. Though, Kosuke is likely to succeed against Righties and thus he is adequate protection while allowing Soriano to hit in the leadoff spot. I don't know that I agree with that - but that's Lou's reasoning.