You definitely want to get in early, rather than laying x mins to go, lay when the market is formed enough, usually a day prior, so you get the benefit of odds movement.

Consider two teams, no draw.

Team A is $1.32
Team B is $4.20

Lay them for stake $10 each

Odds sometime later...
Team A $1.27
Team B $4.60

Back them for stake $10 each

You are left with
Team A -.50c if it wins
Team B +$4.00 if it wins

You can see the odds advantage here.
Essentually you've layed team A at odds of $1.125 or backed team B at odds of $9.00

If you get my drift, regardless of this particular outcome, long term you're getting overs both ways.

*AFL Collingwood v Carlton was used in this example.

Thanks for the clarification CP, anything that can be used 24/7 interests me. Once i get my bankroll back up and running i'll have to look into it.

aaaah ok i think i see. so your laying both and then backing both outcomes just before the event and the price movements generally either way generally delivers a profit?

Yes, I came up with this because of the declining Aus racing liquidity early, and with daylight saving the UK racing scene was taking too much out of me. (always staying up longer than intended) and then being no good the next day.
There's enough sports going off around the world at different times to warrant picking and choosing.

Just be extremely careful of result driven markets.
In other words, performance in another event affects the odds in this event.
Like final 8 or premiers etc.

So lets do some real life examples:

AFL:

GWS vs Port Adelaide
Lay at $12.50
Lay at $1.08

Adelaide vs Melbourne
Lay at $1.10
Lay at $10.50

Brisbane vs Sydney
Lay at $4.50
Lay at $1.25

Carlton vs Collingwood
Lay at $6.00
Lay at $1.19

Essedon vs Bulldogs
Lay at $1.34
Lay at $3.75

That should do for a quick test.

Only Carlton V Collingwood is in play at the moment.
I posted the two odds before the game went inplay.

sorry yep I just went down the list and grabbed a few out. Exclude that one.

Lose .50c on the Collingwood result.

Will update trade prices from UB's list.

Hi CP, thanks for this but I'm probably missing something. Wouldn't the fave team win more often and wouldn't they normally firm therefore losing more often?

Are you talking about two team bets with no draws or do you also do this with drawers in soccer?

And what type of player markets are you talking about?

Sorry for the questions but it seems counter-intuitive (I didn't think I'd use that word this year).

One more question - do you take the lay bet available there and then or do you place an unmatched lay bet a few ticks away like UB said?

The fave team will win more often especially at those sub $1.30 odds.
But I lose .50c or win $4.00 based on the previous example.
Sometimes the favourite team does drift and the outsider firms.
I do this for soccer comprising a draw, tennis, NRL and sometimes cricket.
I only do Match Odds not sub markets, purely for liquidity purposes.

I can only urge you to either follow it here for a while or grab Betfair's sports data, to see the advantage.

Essentially I backed Team B Carlton @ $9.00 using this method, when the last traded price before the game was roughly $4.60.

Assuming that Betfair markets are accurate (prior to commission deductions) one has to make a profit.
Or I layed Team A @ $1.125 when the last price was close to $1.27.

Therein lies the edge, regardless of the frequency of odds on favourites getting up.