Here's how I think about our contest: If you only had backtesting, you could win by fitting. If you only had 1 month of paper trading, you could win by luck (taking excessive risks).

But our contest is 2 years of backtesting + live trading for a month. I don't think it is likely you can both overfit and be lucky with one strategy.

Assuming you blackbox test the algorithms, you could include some signatures of past data. If those signatures are detected, you know the future and can trade optimally. If they are not detected, go for blind luck.