Bacrot is 23, Kamsky is 32 (better than 52!... stamina counts in this game)
Bacrot finished third at the 2005 fide world cup beating Alexander Grischuk for bronze which seems to be notable.
Kamsky seems to have taken a long time off.
Maybe Kamsky is fundamentally the better player according to your source and who is bent on making a comeback?
Worth lookin into.