Arbitrator George Nicolau rules in favor of the Players Association saying that the 26 major league owners colluded and were aware of a databank that detailed 1987 salary offers. The owners will be forced to pay significant damages to the affected players.

On July 18, 1990 — Arbitrator George Nicolau rules in favor of the Players Association saying that the 26 major league owners colluded and were aware of a databank that detailed 1987 salary offers. The owners will be forced to pay significant damages to the affected players.

Source:
Baseball Reference July 18