SELECT "Finish" FROM table_51642 WHERE "League" = 'nl' AND "Percentage" < '0.726' AND "Year" > '1897' AND "Franchise" = 'pittsburgh pirates'
What was the Finish when NL was the League, the Percentage was under 0.726, the Year was larger than 1897, and the Franchies was the Pittsburgh Pirates?
CREATE TABLE table_51642 (
    "Year" real,
    "Franchise" text,
    "League" text,
    "Percentage" real,
    "Finish" text
)