Maybe you should have to submit and have it ran against a secret program that covers many areas of an implementation, so it's unknown precisely what needs to be

Maybe you should have to submit and have it ran against a secret program that covers many areas of an implementation, so it's unknown precisely what needs to be optimized to improve on the test. Have a limit for how often you can retest it to so the only real way to be the fastest is to optimize lots of stuff which is a net win for language users.