Team A was 2 wins and 4 losses in the following match, and failed to qualify, indicating that Team A was always *** 19 wins 17 losses and failed to qualify. Then team B must win at least 19 and lose at least 17, that is, win at least 4 games in the next 5 games and beat team A in the game.

The sentence "one of the games narrowly beat team B by four points" first shows that team A lost to team B before. If Team A loses to Team B later, Team B should qualify under the same conditions (i.e. Tongsheng 19+ 17).