Here's a mechanical trading system for the e-minis that's posted on a free site. How do I know if this is a good trading system or not? What do system traders look for in these performance summaries? What's the most important piece of data? Is it net profit, profit factor, average trade net profit, percent profitable, or something else? What does the profit factor mean? What does it mean if a system is over-optimized? I have a lot more questions, but I'll leave it at that for now.