Is Your Diversification Target Too High?

My diversification target is 15 to 20. Research has shown that there's like a graph of how your risk lowers with each position you add. And when you hit around 20 to 25 companies, it really saturates and adding another position doesn't really make you any more diversified. So in order to try to beat the market, you have to be a little bit less diversified than the market.