CREATE TABLE table_name_37 (match INT, ground VARCHAR, opponent VARCHAR)

What match number has a ground of H and the opponent Chelsea under 18s?
SELECT AVG(match) FROM table_name_37 WHERE ground = "h" AND opponent = "chelsea under 18s"
SELECT AVG("match") FROM "table_name_37" WHERE "chelsea under 18s" = "opponent" AND "ground" = "h"