"Gandalf lied, he was no wizard. He was clearly a high level fighter that had put points in the Use Magic Device skill allowing him to wield a staff of wizardry. All of his magic spells he cast were low level, easily explained by his ring of spell storing and his staff. For such an epic level wizard he spent more time fighting than he did casting spells."
[...]"That's why when he faced a real wizard like Sarumon, he got stomped in a magic duel. He had taken no feats or skills useful to a wizard. If he had used his sword he would have carved up Sarumon without effort."