I havent seen a rule based system posted for quite awhile so here is one from the vault.
No results though as I havent ever used it (not that PAST results are of any use anyway)
i.e The past pattern can never reproduce itself.

Mark down the top 6 in the betting - paper or opening bookie quotes.

Multiply the prices X 1.2.

Bet all at the new price or better.

Cheers