A plays B.  By symmetry, assume A wins.  A plays C
IF A WINS, D vs E, F vs G, winners play, and winner plays A best-of-3
IF C WINS, C plays D
   IF C WINS, E plays F.  By symmetry, assume E wins.  E plays G
      IF E WINS, C plays E best-of-3
      IF G WINS, C plays G
         IF C WINS, C plays E twice (C wins ties)
         IF G WINS, C plays G twice (G wins ties)
   IF D WINS, A plays E
      IF A WINS, A plays C
         IF A WINS, F plays G, the winner plays D, and the winner plays A
         IF C WINS, F plays G, the winner plays C, and the winner plays D
      IF E WINS, D plays E
         IF D WINS, D plays F, D plays G, and the winners play
         IF E WINS, B plays F, the winner plays G, and the winner plays E