Been thinking of this for awhile now, is it possible to back every horse in a race and still win in the long run? I'm not talking about dutch betting, betting the same amount on every horse.

We now that 1st Fav win 33% of races with a return of 94% you would need to back the Fav at 7% higher odds to be in front.

Same for 2nd Fav 20% win return of 89% so you would need 12% better odds to come out in front.

and so on right down to the longest odds. so in theory you should win on every runner.
Would this work???