CREATE TABLE table_72851 ("Position" TEXT, "Team #1" TEXT, "Agg." TEXT, "Team #2" TEXT, "1st leg" TEXT, "2nd leg" TEXT)

How many positions correspond to a 1-3 1st leg?
SELECT COUNT("Position") FROM table_72851 WHERE "1st leg" = '1-3'
SELECT COUNT("Position") FROM "table_72851" WHERE "1st leg" = '1-3'