The announcement of Luis Razia as second driver at Marussia means that the two halves of the 2013 F1 grid have a very different character; with stability in the front half and wholesale change in the second half of the grid, which features five drivers who have never started a Grand Prix before. Whereas among Red Bull, Ferrari, McLaren, Lotus, Mercedes and Force India there are currently only two driver changes; Hamilton to Mercedes, replaced at McLaren by Perez and a new driver at Force India. The other five teams have seen enormous change. Sauber has two new drivers, Hulkenberg More…