BIDEN: Biden went on the offensive in hopes of regaining ground lost by President Barack Obama's lackluster debate performance. An experienced debater, Biden is comfortable with the attack dog role. But the vice president appeared to get angry and may have lost his cool
RYAN: This was the Wisconsin congressman's first time on the national debate stage. As House Budget Committee chairman, he's a whiz on federal spending and tax policy. Not so much on knowledge of foreign policy and national security.
BATTLE OF THE AGES: Old vs Young. Little experience vs. lots of experience. At 42, Ryan is the same age as Biden's younger son. Ryan suggests the generational divide gives him an edge over 69-year-old Biden and wider appeal. But Biden's an energetic performer who prides himself on an ability to connect with regular Americans.
MODERATOR: Martha Raddatz of ABC News ran the show better than the last moderator and asked some sharp questions, while more aggressively reining in the candidates.