It all depends on how you view standard deviations from the mean. I would agree that once a player hits 28, that enters the 1-2 year contract maximum. The prime argument is an interesting one. It would be interesting to see production at age statistics for the AFL.
Last 10 years of brownlow medal
YearPlayerTeam
2012Jobe Watson 27years of age
2011Dane Swan 27 years
2010Chris Judd 27 years
2009Gary Ablett Jr 25 years
2008Adam Cooney 23 years
2007Jimmy Bartel 23 years
2006Adam Goodes 26 years
2005Ben Cousins 28 years
2004Chris Judd 21 years
2003Mark Ricciuto 28 years
Nathan Buckley 31 years
Adam Goodes 23 years
The youngest Brownlow medal winner was Dick Reynolds at the age of 19 in 1934.
The oldest Brownlow medallist is South Melbourne’s Barry Round in 1981 - he was 31 years, 238 days.
Only one player since 1994 has won the medal 30 years or older - Nathan Buckley with Collingwood in 2003, at 31 years, 57 days.