>As described by Zuckerman, Medallion’s strategy involved constantly opening and covering thousands of short-term positions, both long and short. According to Robert Mercer, one of Medallion’s key investment managers, Medallion was right on only about 50.75% of its trades. Nonetheless, he stated that taken over millions of trades that percentage allowed the firm to make billions. It is worth noting that engaging in millions of trades suggests that the transaction costs would be significant. The fact that the reported gross returns are after trading costs, makes Medallion’s performance even more extraordinary. It also implies that Renaissance was apparently particularly effective in minimizing such costs.

If you can actually reliable make 50.75% of your trades successful all it takes is making enough trades and reducing costs. The moral of the story is anyone who talks about a 50.80%+ success rate is lying to you. I would go even further and even say the ones talking about a 50%+ success rate are probably lying.