Table schema:
CREATE TABLE table_name_51 (co_champions INTEGER, records VARCHAR, pct VARCHAR, mrc_championships VARCHAR)

Question: What is the highest value for co-champions when the PCT is less than 0.786 and MRC championships is 6 with records of 88-45-6?
SQL: SELECT MAX(co_champions) FROM table_name_51 WHERE pct < 0.786 AND mrc_championships = 6 AND records = "88-45-6"