List the maximum scores of the team Boston Red Stockings when the team won in postseason?
SELECT max(T1.wins) FROM postseason AS T1 JOIN team AS T2 ON T1.team_id_winner  =  T2.team_id_br WHERE T2.name  =  'Boston Red Stockings';
maximum scores = MAX(T1.wins); team = Boston Red Stockings; when the team won in postseason refers to T1.team_id_winner = T2.team_id_br and T2.name = 'Boston Red Stockings';