CREATE TABLE table_13206 ("Date" TEXT, "Visitor" TEXT, "Score" TEXT, "Home" TEXT, "Record" TEXT)

Who was the visitor for Chicago Black Hawks on May 6?
SELECT "Visitor" FROM table_13206 WHERE "Home" = 'chicago black hawks' AND "Date" = 'may 6'
SELECT "Visitor" FROM "table_13206" WHERE "Date" = 'may 6' AND "Home" = 'chicago black hawks'