Classic offense vs. defense debate.
McCain played good offense for the first half hour of this debate. He seemed like he had his anger under control. His answers were cohesive. He didn't have any major senior moments.
Obama played it safe and let the old man tire himself out.
By the half hour mark McCain was clearly physically exhausted. You could hear his guttural gasps for air. You could see how rattled he was getting as Obama carefully baited him.
By about the 45m-1h mark McCain was glaring at Obama. He was so excited to start attacking Obama that he had trouble speaking at times. His answers got more disjointed.
The last half hour Obama clearly won. He was energetic and calm.