Question: WHat matcH number Has a ground of H and tHe opponent Chelsea Under 18s?
SQL: SELECT AVG("Match") FROM "2-18539546-21" WHERE "Ground" = 'H' AND "Opponent" = 'Chelsea Under 18s';

Question: On wHat date is tHere a matcH lower tHan 14 witH a ground of H and tHe opponent Aston Villa Under 18s?
SQL: SELECT "Date" FROM "2-18539546-21" WHERE "Match" < 14.0 AND "Ground" = 'H' AND "Opponent" = 'Aston Villa Under 18s';

Question: On what date is there a score1 of 2 - 4 with the opponent Chelsea Under 18s?
SQL: SELECT "Date" FROM "2-18539546-21" WHERE "Score1" = '2 - 4' AND "Opponent" = 'Chelsea Under 18s';