If you could only make one decision in your investment strategy, what would it be? Would you concentrate on picking the best securities? The best ETFs or mutual funds? Would you focus exclusively on trying to time your asset allocation/rebalancing choices? Or maybe you’d spend a lot of time deciding if Asian stocks would beat European equities in the foreseeable future. Or how about managing the risk, however defined, like a hawk? In any case, the question is simply this: Which variable in the money game is likely to have the most influence on the end result of performance?