There are zillions of possible plans and alternatives for both sides in the last moves. 9.b4 is not the most popular: 9.Nbd2 is most often played.
1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1c4 Every single elite tournament nowadays feature a bunch of games in the Italian Opening. The Giuoco Piano, as the name says, is characterized by slow maneuvering, and some of these games tend to be boring. Not this one, though. 3... g8f6  4. d2d3  4... f8c5  5. e1g1  5... d7d6  6. c2c3  6... a7a6  7. a2a4  7... h7h6  8. f1e1  8... c5a7 