A strategy \(s_i\in S_i\) maximizes expected utility for player \(i\) with respect to \(p\in \Delta(S_{-i})\) provided for all \(s_i'\in S_i\), \(EU(s_i,p)\ge EU(s_i',p)\). In such a case, we also say \(s_i\) is a best response to \(p\) in game \(G\).