Searching for an Axis-Parallel Shoreline

We are searching for an unknown horizontal or vertical line in the plane under the competitive framework. We design a well-suited framework for all cylcic strategies that result in two-sequence functionals. For optimizing such functionals we apply a method that combines two main paradigms. The given solution shows that the combination method is of general interest. Finally, we obtain the current best strategy and can prove that this is the best strategy among all cyclic strategies which is a main step toward a lower bound construction.