CREATE TABLE table_51866 ("Date" TEXT, "Visitor" TEXT, "Score" TEXT, "Home" TEXT, "Leading scorer" TEXT, "Record" TEXT)

What is the home team of the game where the Grizzlies were the visitor team and Rudy Gay (21) was the leading scorer?
SELECT "Home" FROM table_51866 WHERE "Visitor" = 'grizzlies' AND "Leading scorer" = 'rudy gay (21)'
SELECT "Home" FROM "table_51866" WHERE "Leading scorer" = 'rudy gay (21)' AND "Visitor" = 'grizzlies'