THERE has been an enormous betting plunge on Hawthorn midfielder Sam Mitchell to win this year's Brownlow Medal.

It follows a prediction from professional punter Sean Brady on The Footy Show on Thursday night, with Mitchell backed from $21 into $7 and the third line of betting.





"Mitchell's a proven votegetter and often attracts big support with us, but this is biggest move we've ever seen for him," the TAB's Adam Hamilton said.

"He was $21 on Monday, into $17 by Tuesday and then the big crunch came last night and this morning where his odds have tumbled into $7."





Centrebet reported a similar plunge, with Mitchell's odds also tumbling at the rival company.





"Sam Mitchell has been backed from $21 into $6.50 in the last 24 hours," Centrebet's Michael Felgate said.





"Since this morning 90 per cent of bets taken on the Brownlow have been on Mitchell.

"In a four-hour period we have taken bets to win more than $150,000 on him.

"A plunge this big is unheard of considering Gary Ablett has been a long odds-on favourite for most of the year."





Ablett remains favourite for the Medal with Joel Selwood behind. Mitchell has become a clear third favourite.

Brady has a solid history in successful Brownlow punting. He won more than $1 million following Chris Judd's 2010 victory and predicted the Jobe Watson-Trent Cotchin quinella last year winning $250,000.