The test results for a baked russet are approximately 25% higher than the same potato in the raw form. It may appear odd or counter-intuitive, but you have to think of the baking process and how that causes water to evaporate from the food. What you're left with is a potato that is denser with less water in the baked version. That explains why 100 grams of baked has more nutrition than 100 grams of it raw.
ORAC Source
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010