I've once read that Andropov already prefered Gorbachev as his successor, just as Brezhnev prefered Chernenko to succeed him.
Otherwise, I've been interested in Soviet history, but particularry Stalin era
Romanov may have won in 1984 if some old non-Brezhnevians, like Gromyko, Solomentsev, Shcherbitsky, gathered with young Andropovians like Gorbachev, Vorotnikov and Chebrikov (KGB) and with the Brezhnevian (but more Ustinovian...) Ustinov.
But they all picked the harmless Chernenko, with the "youngs" konwing he would die soon.
Romnaov was a Leningradian, which was, at the time, not a good thing...
I'm not sure Andropov had a clear choice. That was more Kulakov who gave a boost to Gorbachev's career. Andropov was kind to Gorby, but he hadn't chosen any successor.
Gorbachev won in 1985 because Gromyko didn't support the Brezhnevian candidate, Grishin (1st secretary in Moscow), who was only supported by Tikhonov (PM). Romanov was already out because of corruption and weird personality.
A fascinating time between Suslov's death and Kirilenko's demise in 1982 up to 1989...