This main variant of losing chess was weakly solved in October 2016; White is able to force a win beginning with 1.e3. Some lines are trivial (1…d6, 1…d5, 1…Na6, and 1…g6 lose in less than 20 moves), others are quite simple (1…Nf6, 1…h6, 1…e5, 1…f5, 1…h5, 1…f6, 1…a6, 1…a5 lose in less than 30 moves, subject to knowledge of the theory), some are quite complicated (1…Nh6, 1…Nc6, 1…c6, the win in which may require about 60 moves). The most difficult are the following five openings (in order of increasing difficulty): 1.e3 g5 (Wild Boar Defence), 1.e3 e6 (Modern Defence), 1.e3 b5 (Classical Defence), 1.e3 c5 (Polish Defence), and 1.e3 b6 (Liardet Defence).