Perhaps you are new to the master limited partner space. If so, here is lesson No. 1: don't bother looking at quarterly earnings results. Sure, on paper the quarterly earning results at Energy Transfer Partners (NYSE:ETP)Magellan Midstream Partners (NYSE:MMP), and ONEOK Partners (NYSE:OKS) looked great. But the fact of the matter is that the income statement is not that important. Instead you should be looking at the cash flow statement. 

Why is the cash statement so important? It all has to do with the nature of the business. Tune into the video below to find out the important numbers you should look for when evaluating these companies on a quarterly basis and get a peek at what those numbers were this past quarter for the three MLPs.

Tyler Crowe owns shares of Magellan Midstream Partners, L.P.. You can follow him at under the handle TMFDirtyBird, on Google+, or on Twitter @TylerCroweFool.

The Motley Fool recommends Magellan Midstream Partners, L.P. and ONEOK Partners, L.P.. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.