<div class='user_solution'><span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">1.d6+! </span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">With the following <span> </span>lines :</span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">A) 1...Kb7 2.Na7! Bh5+</span></b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">2...Rxd6 3.Kxe8 Rxe6+ 4.Kd7!= <i>(no 4.Kf7? Re5! 5.g4 Ra5 6.Kf6 Ra6+ 7.Kf5 Rxa7–+) </i></span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">2...Ba4+ 3.Ke7 Rg8 4.d7! (4.g4? Rg7+ 5.Kd8 <i>(5.Kf6 Rxg4 6.d7 Rd4 7.Nc8 Kc7 -+) </i>5...Rg6 6.Ke7 Bb3 7.Nb5 Rxe6+ 8.Kf8 Kc8–+) 4...Kc7 5.Nc8!=;</span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">3.Ke7 Re8+ 4.Kf6 Bg4 5.d7 Rxe6+ 6.Kg5 Kc7 7.Nb5+ Kxd7 8.Kxg4 Re4+ 9.Kf5!=;</span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">B) 1…Kxc8<span>  </span>2.e7 Rxd6 3.Kxe8 Re6 4.g4! </span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">4.Kf8? Kd7–+</span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">4...Kc7 5.g5 Kd6 6.g6 Rxe7+ 7.Kf8 Ke6 8.g7 Rf7+ 9.Kg8 Kf6 </span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">9...Rf1 10.Kh8 /h8 .Rh1+ 11.Kg8 Kf6 12.Kf8 Ra1 13.g8N+!=</span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">10.Kh8 Rxg7= </span></b><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">stalemate<span></span></span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">C) 1...Kc6 2.Ke7 Rxc8 3.g4!</span></b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><i><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">3.d7? Bxd7 4.exd7 Rc7!–+</span></i></span> <span class="MsoNormal" style="text-align:justify;display:block;"><i><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></i></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;">3...Ra8 4.d7 Bxd7 5.exd7 Ra7 6.g5 Rxd7+ 7.Kf6 Kd6 8.g6 Re7 9.g7 Re8 10.Kf7=</span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><b><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></b></span> <span class="MsoNormal" style="text-align:justify;display:block;"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"><span> </span>Derivation of the study of<span>  </span>R. Richter - Schach 1985<b> </b></span></span> <span class="MsoNormal" style="text-align:justify;display:block;"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></span> <p class="MsoNormal"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></p> <p class="MsoNormal"><span style="font-family: &quot;Times New Roman&quot;, &quot;serif&quot;;"> </span></p></div>