Computer Chess Rules

Here is a short set of rules I have set out for when I pit computers and software together for chess matches.
First I created an initial leader board based on a tournament I created of mordern chess engines. In this tournament all engines started at 2000 ELO, and played variuos time constraints.
All new challengers will start at 1500 ELO
All new challengers will have their difficulty rating sarting at the lowest settings. (this is beacause of some older systems each move can take up to hours to make.)
Everytime a system/software loses, it will be at their next difficulty level the next time it plays.
Evertime we get 5 new challengers all systems/software will play until they have all reached an equal amount of games played.