CREATE TABLE table_203_506 (id DECIMAL, "opponent" TEXT, "played" DECIMAL, "won" DECIMAL, "lost" DECIMAL, "drawn" DECIMAL, "% won overall" TEXT)

how many teams did they not lose to ?
SELECT COUNT("opponent") FROM table_203_506 WHERE "lost" = 0
SELECT COUNT("opponent") FROM "table_203_506" WHERE "lost" = 0