Has an MLB game ever ended 9-9?
It has. 9-9 has been a MLB final 31 times in 235,971 games. The first was Detroit Wolverines and Troy Trojans drew on August 31, 1882; the latest was St. Louis Cardinals and Cincinnati Reds drew on September 3, 1949.
That makes 9-9 the 157th most common final score out of 330 that have ever occurred in MLB. One point away, 10-9 has happened 844 times and 9-10 has happened never.