CREATE TABLE table_63137 ("Match" FLOAT, "Date" TEXT, "Competition or tour" TEXT, "Ground" TEXT, "Opponent" TEXT, "Score1" TEXT)

What ground had a match smaller than 6 and Chelsea Reserves as the opponent?
SELECT "Ground" FROM table_63137 WHERE "Match" < '6' AND "Opponent" = 'chelsea reserves'
SELECT "Ground" FROM "table_63137" WHERE "Match" < '6' AND "Opponent" = 'chelsea reserves'