Mike Bossy the Scoring Machine is a pinball machine manufactured by Game Plan, Inc. as a prototype in 1982, featuring New York Islanders hockey star Mike Bossy. There was only one machine produced. Designed by Ed Cebula, it was the only professionally endorsed pinball machine produced by Game Plan.
Game Plan produced amateurly endorsed pinball manchines.
The context mentions that Game Plan only produced one professionally endorsed pinball machine, which could mean it produced non-professional sport endorsed pinball machines (like from olympic athletes) or it's possible they didn't. We can't know for sure. The language of "amateurly endorsed" is probably a difficult phrasing for the system to understand so it thought the statement was incorrect. 