Hi Benny,
It should work well if you can maintain a 60% SR like you have stated.

I am assuming you use other filters because the average SR for the 2 favs is generally 50%.

One could split the bet half & half or use a 60%/40% split which I feel would be the stronger option if prices have a gap between them.
e.g. 3.50 & 5.00
$10 bet on race
60% of bet on 3.50 x 6.00 = Ret 21.00
40% of bet on 5.00 x 4.00 = Ret 20.00

That idea of yours usually works best in fields of <=11 runners.
The smaller the field the greater the chance of the 2 favs of getting up.
The trick is trying to secure the fav at $3.50, do that & your laughing like a Hyena.

Any more & you will experience days with runs of 8-9 outs in a row.
On a regular basis.

Generally, one would like to see those 2 selections narrowed down to one, if that can be successfully done, at least 50% of the time.
SR would then be 30% thus returning greater profit if things go our way.

Maybe you would like to get back to us if you have invented a simple plan to successfully separate them 50%+ of the time.

I can see backing 2 runners a race would be a lot more fun than backing just 1 runner a race.

__________________
Cheers.