How many mens doubles took place in 1970/1971?
CREATE TABLE "table1_12266757_1" (
  "season" text,
  "mens_singles" text,
  "womens_singles" text,
  "mens_doubles" text,
  "womens_doubles" text,
  "mixed_doubles" text
);
SELECT COUNT("mens_doubles") FROM "table1_12266757_1" WHERE "season"='1970/1971';