The Cats have tumbled from an opening quote of $1.72 into $1.60 as Richmond's big man woes continue.

Richmond, which opened at $2 has drifted out to $2.20.

In the Port Adelaide versus Western Bulldogs game at Football Park, one big betting punter has snapped up the Power at $1.22, placing $20,000 on it to win.

Brisbane opened at the shortest price yet this season, $1.06, to beat Carlton with TAB Sportsbet holding a total of $4000 to continue the Blues' losing streak.

St Kilda, which takes on Hawthorn on Sunday at Colonial Stadium, is unwanted in betting with TAB Sportsbet holding just $95 on it to win.

And the normal punter theory that you back a team that's lost its coach mid-season hasn't eventuated, with Sydney turned in only slightly from $1.65 into $1.60 for its match against Fremantle.

West Coast is favoured to continue its unbeaten run at home this season against Adelaide, opening at $1.72 and firming into $1.65, while Adelaide has drifted from $2 to $2.20.

Essendon ($1.55) has firmed against Melbourne ($2.40) while in premiership betting one punter has placed $10,000 on Port Adelaide for a return of $35,000.

Hawthorn's Shane Crawford is now outright favourite to win his second Brownlow Medal after $2000 was placed on him at $7, bringing his odds in to $6.50.

West Coast captain Ben Cousins is second favourite at $7 and the Western Bulldogs' Luke Darcy $8.

The winner of this week's TAB Sportsbet competition is Kathleen Elliott from Belmont, who has placed her $25 betting voucher on Sydney at home to beat Fremantle.

Each week the Geelong Advertiser and TAB Sportsbet give one lucky reader a $25 Sportsbet voucher to wager on the weekend's round of AFL football.

To enter, post entries to the Geelong Advertiser TAB Sportsbet Competition, PO Box 1573, Geelong 3220.