Mosman Cricket Club and NSW fast bowler Greg Rowell was a clear winner of the 1990-91 Bill O'Reilly Medal for the best and fairest in Sydney Grade Cricket.

The top 5 for 1990-91

30 points - Greg Rowell (Mosman Cricket Club)
24 points - Phil Weatherell (Sutherland District Cricket Club)
23 points - Richard Stobo (Gordon District Cricket Club)
21 points - Ian Austin (Randwick District Cricket Club and Jamie Baker (UNSW Cricket Club)

Sutherland District Cricket Club won the teams award with 106 points with Balmain Cricket Club second on 104 points.

https://www.cricconnect.com/profile/1191/nsw-premier-cricket/blog/1875/mosman-cricket-club-fast-bowler-greg-rowell-won-the-1990-91-bill-oreilly-medal