CREATE TABLE table_50823 ("Date" CLOB, "Tournament" CLOB, "Winning score" CLOB, "Margin of victory" CLOB, "Runner ( s ) -up" CLOB)

Who is the runner-up at the Chicago challenge?
SELECT "Runner(s)-up" FROM table_50823 WHERE "Tournament" = 'chicago challenge'
SELECT "Runner(s)-up" FROM "table_50823" WHERE "Tournament" = 'chicago challenge'