CREATE TABLE table_58039 ("Season" TEXT, "Tier" FLOAT, "League" TEXT, "Pos." FLOAT, "Postseason" TEXT, "Turkish Cup" TEXT)

What is the average position for tb2l teams promoted champion?
SELECT AVG("Pos.") FROM table_58039 WHERE "League" = 'tb2l' AND "Postseason" = 'promoted champion'
SELECT AVG("Pos.") FROM "table_58039" WHERE "League" = 'tb2l' AND "Postseason" = 'promoted champion'