There is an ongoing debate about the methods used for calculating and decomposing portfolio rates of return.  This article adds new arguments to this discussion as the author describes a method for decomposing the portfolio's MWR/IRR and the portfolio's respective excess return.  As shown, this methodology can easily be applied to the absolute or dollar-oriented analysis or the IRR as the "true" MWR perfectly fits with the absolute profit and loss figures.  By reading this article, the reader should get questions answered relating to the impact of timing effect of cash flows to the return calculation and decomposition.