CREATE TABLE table_203_780 (id NUMBER, "rank" NUMBER, "diver" CLOB, "preliminary\ points" NUMBER, "preliminary\ rank" NUMBER, "final\ points" NUMBER, "final\ rank" NUMBER, "final\ total" NUMBER)

how many drivers raced in the preliminary round ?
SELECT COUNT("diver") FROM table_203_780 WHERE NOT "preliminary\npoints" IS NULL
SELECT COUNT("diver") FROM "table_203_780" WHERE NOT "preliminary\npoints" IS NULL