Thanks, Darryl. kailey, that IS the mathematical solution - at least the one predicated on you plugging in the dog bet, the dog odds and the favorite odds - go see the post I put up before this one and you'll see the equation. Other equations exist for solving how much to bet on the dog based what you bet on the favorite, and also for calculating a scalp in those situations where both of the odds are positive, like a +110 and +100 ML scalp. I have no idea if this exists on someone's web page - that was why I recommended you use Excel to define the equation (or get someone to do it for you).
I'd like to point out that scalping serves another very helpful purpose: when you're trying to get your money out of a stiff or near-stiff book, or perhaps a book you're no longer comfortable keeping your money in but you don't have enough there to bother with a withdrawal. Knowing how to pay the least to do this is a good tool to have. Sure, you're not guaranteed of succeeding in getting the money out, but taking high ML dogs at the book you want your money out of is not a bad way to do it. And if it's a stiff book, sometimes you might scalp but lose money on the try (for example, say your dog was +400 but the favorite is -420), just to get the cash out - knowing how to solve another equation shown below will minimize your net loss involved in that case:
A = amt you bet on the dog in dollars and cents ($100)
B = dog odds (400)
C = favorite odds (420 – though actually -420, leave the minus sign off)
=( (A+ ((B/100) * A)) * (C/100) ) / (1 + (C/100) )
=( ($100 + ((400/100) * $100)) * (420/100) ) / (1 + (420/100) )
=( ($100 + (4 * $100)) * (4.2) ) / (1 + 4.20)
=( $100 + $400 ) * (4.2) ) / (5.20)
=( $500 * 4.2 ) / (5.20)
=($2,100) / (5.20)
=$403.84 is the amount you must bet on the favorite to pay the least possible cost
Dog wins: win $400 – loss $403.84 = -$3.84
Fav wins: win $96.15 – loss $100 = -$3.85
Note: the 2 amounts are off by a penny due to rounding - wasn't going to show you more than 2 decimals.
Excel can do this for you, instantly - if you don't know it, find someone who does. GL