The basic model of the balancing and settlement rules (GABi) as well as the billing and settlement of excess/shortfall quantities (MMMA) are essential components of the gas network access model in Germany. The gas network access model enables non-discriminatory supply to end customers within Germany. The author analyzes the extent to which the German gas network access model offers market participants opportunities to optimize profits by exploiting regulatory provisions, either by achieving cost advantages or maximizing revenues. This question is highly relevant, as the basic model of the balancing and settlement rules has only recently come into effect and is continuously subject to adjustments by the Federal Network Agency. The book provides a comprehensible overview of the energy sector, given the complexity of the regulatory subject matter.