Table: steaua_player_stats_2
Columns: country
player_name
period
position
matches
goals

Question: Name the player name with matches of 51
SQL: SELECT "player_name" FROM steaua_player_stats_2 WHERE "matches" = '51'

Question: Name the position for brazil 2008 with goals of 0 1
SQL: SELECT "position" FROM steaua_player_stats_2 WHERE "country" = 'brazil' AND "period" = '2008' AND "goals" = '0 1'

Question: Name the goals with matches of 21
SQL: SELECT "goals" FROM steaua_player_stats_2 WHERE "matches" = '21'

Question: Name the period with matches of 0 0 of portugal
SQL: SELECT "period" FROM steaua_player_stats_2 WHERE "matches" = '0 0' AND "country" = 'portugal'