CREATE TABLE table_204_127 (id NUMBER, "outcome" CLOB, "no." NUMBER, "date" CLOB, "tournament" CLOB, "surface" CLOB, "opponent" CLOB, "score" CLOB)

which surface was played on the least ?
SELECT "surface" FROM table_204_127 GROUP BY "surface" ORDER BY COUNT(*) LIMIT 1
SELECT "surface" FROM "table_204_127" GROUP BY "surface" ORDER BY COUNT(*) FETCH FIRST 1 ROWS ONLY