It needs to be tested in both bull and bear markets. His time period was all bull (S&P +22%). I've been beating the S&P on a dividend play, but it's all in an up market as well, and the upward movement may be amplifying my choices on the positive side. A down market may have the opposite effect, and amplify on the negative. Also, I may have just hit a market rotation at the right time, which is not repeatable for me (since I don't know how to predict it). So I don't trust my results unless/until it also outperforms in a down market.