Even if Pat Stay could hang with Eminem or hold his own lyrically, he doesn't have the voice, the flow, or the charisma. If you ever noticed, a lot of black guys or other rappers who ever tried to rap similar to Eminem (except Hopsin) just don't have the same impact or wow factor. It's a simple fact. They could say the same exact rhymes and wouldn't get quite the ovation. Charisma is a factor that does hold weight. I wasn't impressed by Pat Stay, Theasurus was actually much stronger. But even he doesn't have the same charisma as Em. They'll never have the amount of Stans. So you have to look at the whole package, not just one aspect, like say, a punch line. Two actors could have the same exact lines for an acting role, one is going to play that role better, even though they performed essentially the same role. In 8 Mile, Lickity and Lotto went toe to toe with Em. But they didn't have the charisma. Yes I know it's a movie, but people are going to be more impressed with who they like better.
Also, Pat's insults were very very generic. And not witty enough (rapping about someone's daughter redundantly for 5 minutes) If you watch Em battle, he will talk about things that are more pertinent. Pat kinda raps about one subject, goes to left field with it, then hops on to the next subject, so sporadically. The rhyming is there, but not the same level of intricacy and pertinence on the matter at hand. I mean, I don't get blown away in a rap battle when he's referring to himself as a winning chess piece. And where is the flow? Another thing. Sometimes less is more. Em can say more in one line than some of these cats can say in 3 bars. These young cats get very embellished in their craft and become very articulate and technical. But the exuberance and, for lack of better world, perception of realism is not quite there. Just like Em said, a million fish in the sea.
Having said that I'm upset that Eminem made Recovery so poorly. He made it for mainstream pop fans. He dumbed down his material and his beats on purpose. Commercially, yes, it worked.