CREATE TABLE table_31620 ("Year" CLOB, "Men's singles" CLOB, "Women's singles" CLOB, "Men's doubles" CLOB, "Women's doubles" CLOB)

Who played men's singles in 1951?
SELECT "Men's singles" FROM table_31620 WHERE "Year" = '1951'
SELECT "Men's singles" FROM "table_31620" WHERE "Year" = '1951'