CREATE TABLE table_16645 ("Edition" FLOAT, "Zone" TEXT, "Round" TEXT, "Date" TEXT, "Against" TEXT, "Surface" TEXT, "Opponent" TEXT, "Outcome" TEXT, "Result" TEXT)

How many rounds were 2r?
SELECT COUNT("Result") FROM table_16645 WHERE "Round" = '2R'
SELECT COUNT("Result") FROM "table_16645" WHERE "Round" = '2R'