In theory, Saturday's Australian Open final should be a thrilling battle between the top two players in the world. It should be almost too tight to call.
However, Serena Williams is the 8/15 favourite to beat sister Venus - and the reason is history. Serena has endured much more of a struggle to reach the final sphere, but over the past year, she has won all three other Grand Slams, on each occasion beating her sister in the final.
Those wins, added to another in Miami last spring, mean the younger sibling has now won the pair's last four clashes - and all in straight sets. On each occasion Serena's serving and returning has been better.
Venus may be the fastest returner in the game, but her sister seems to be able to read the delivery and force cracks in her game.
In contrast, Serena - regarded by many commentators as the best female server - has clearly been the more solid on serve.
To prove the point, Serena forced 36 break points in their three Grand Slam finals in 2002 to Venus' 20. They converted 17 and 10 respectively. A look at the double-fault count is also relevant - Serena serving just eight in the three matches, compared with Venus' 25. And finally Serena also out-aced her sister, nine to four.
With this in mind, it is easier to see why Serena is clearly the bookies' favourite.
However, a top price of 4/7 is not the most tempting bet in the world, particularly given the way she struggled to overcome Emilie Loit in round one and then Kim Clijsters - who held two match points against her - in the semis.
At least incentive will not be a problem. Serena will want to complete the 'Serena Slam' of holding all the Major titles at once, but her sister cannot like playing second fiddle and should be determined to hit back.
With set betting never the easiest thing to get involved with, a look at the spreads may be the better call here.
A further look into the double-fault stats shows that between them, the sisters have served 52 in their matches over the past fortnight. Both players have played six rounds so far, so we could expect a final average of just over eight.
But the more relevant stats are those listed above regarding their previous meetings.
This is when the pressure is really on - particularly Venus - so expect more in Saturday's showdown. You can buy at nine with Sporting and this looks the best call.
This would have made a profit in both the 2002 French and US Open finals, with only a small loss at Wimbledon.
And, of course, if this one should go to a deciding set, surely a decent profit will be made.
The ace count may also hold the key to more cash.
The total so far by the Williamses in Melbourne is 64 in the six rounds - in which case you might expect just over ten this time. But previous history shows that the extra reach of the sisters mean they get serves back that no other players would.
A sell at seven with Cantor would have produced a profit in all three Grand Slam finals between the two in 2002.
The down side is if a third set is necessary.
That is also the case by playing the total games market. Total games quotes for the sisters' four 2002 meetings were 18, 22, 21 and 16. In fact the biggest-ever make-up for these two is 27 - and that was almost four years ago.
You can sell at 24 with Sporting, but with that fear a third set will surely be played by these two sooner rather than later, it is probably wise to steer clear of selling.
Buy double faults @ 9 (sporting index) for 1 point.
