Correct answer: Re2-g2 1.Re2-g2 ! zugzwang. 1...Nf1-h2 2.Qe1-g3 # 1...Nf1-g3 2.Qe1*g3 # 1...Nf1-e3 2.Qe1-g3 # 1...Nf1-d2
