Count the number of times the team "Boston Red Stockings" lost in 2009 postseason.
SELECT count(*) FROM postseason AS T1 JOIN team AS T2 ON T1.team_id_loser  =  T2.team_id_br WHERE T2.name  =  'Boston Red Stockings' AND T1.year = 2009;
count the number of times = COUNT(*); team 'Boston Red Stockings' lost = condition on team name and identifying losing instances; in 2009 postseason = filtering by year 2009 in a postseason context;