The plot above shows the results for the last 4 1/2 years for buying the top 5 of 8 asset classes each month. The return was better than SPY. The asset classes in this case were actual ETFs (AGG, EEM, EFA, IWM, IYR, SPY, and TIP) and one commodity index (DJAIG).
The results were significantly better by just buying the top 3 of 8 asset classes. The plot above shows the results over the past 4 1/2 years using the same set of asset classes.
While there was a big drawdown during the market crash, an active approach to asset class allocation would seem to be a good approach to helping to smooth out returns during turbulent market periods.