What is Darrius Heyward-Bey's average with more than 20 yards and less than 80 long?
CREATE TABLE "receiving" (
  "player" text,
  "rec" real,
  "yards" real,
  "avg" real,
  "long" real
);
SELECT COUNT("avg") FROM "receiving" WHERE "yards">20 AND "player"='darrius heyward-bey' AND "long"<80;