Question: How many times in total did the team Boston Red Stockings participate in postseason games?
SQL: SELECT count(*) FROM ( SELECT * FROM postseason AS T1 JOIN team AS T2 ON T1.team_id_winner  =  T2.team_id_br WHERE T2.name  =  'Boston Red Stockings' UNION SELECT * FROM postseason AS T1 JOIN team AS T2 ON T1.team_id_loser  =  T2.team_id_br WHERE T2.name  =  'Boston Red Stockings' );