A New Upper Bound for Max-2-Sat: A Graph-Theoretic Approach
  In {\sc MaxSat}, we ask for an assignment which satisfies the maximum number of clauses for a boolean formula in CNF. We present an algorithm yielding a run time upper bound of $O^*(2^{\frac{1}{6.2158}})$ for {\sc Max-2-Sat} (each clause contains at most 2 literals), where $K$ is the number of clauses. The run time has been achieved by using heuristic priorities on the choice of the variable on which we branch. The implementation of these heuristic priorities is rather simple, though they have a significant effect on the run time. The analysis is done using a tailored non-standard measure. 
Daniel Raible and Henning Fernau