Table: memorial_tourney
Columns: year
player
country
score
margin_of_victory
winners_share
honoree_s

Question: How many countries does honoree Roberto de Vicenzo represent?
SQL: SELECT COUNT("country") FROM memorial_tourney WHERE "honoree_s" = 'Roberto De Vicenzo'

Question: For which country does Keith Fergus play?
SQL: SELECT "country" FROM memorial_tourney WHERE "player" = 'Keith Fergus'

Question: Who won the tournament for Australia in the year when Byron Nelson was Honoree?
SQL: SELECT "player" FROM memorial_tourney WHERE "country" = 'Australia' AND "honoree_s" = 'Byron Nelson'

Question: What was the margin of victory in the year when the honoree was Tommy Armour?
SQL: SELECT "margin_of_victory" FROM memorial_tourney WHERE "honoree_s" = 'Tommy Armour'