<html><head></head><body><div class="ydp264618c3yahoo-style-wrap" style="font-family:Arial, Helvetica, sans-serif;font-size:16px;"><div><div dir="ltr" data-setdir="false"><div><p class="ydp9a50a156MsoNormal" style="margin-bottom:0cm;margin-bottom:.0001pt;line-height:normal;background:white"><span style="font-size:12.0pt;font-family:Arial,sans-serif;mso-fareast-font-family:Times New Roman;color:#1D2228;letter-spacing:-.25pt;mso-fareast-language:DE">The theme of this years Christmas puzzles - delayed
due to the coverage of the WCh match - is Chess960, or Fischerrandom chess. For
our purposes, it's not the basic position decided by lot which is relevant for
us, but the special castling rules and it's possibilities for problem chess. As
always the puzzles had been selected by Werner Keym.<br>
In Chess960, in the starting position the kings are placed somewhere between
the rooks. And as long as king and rook had not moved, long and short castling
is possible, whereafter it's - as usual - Kg1/Rf1 or Kc1/Rd1 (for White).<br>
A special feature here for retro problems is, that the solver has an unusual
wide choice when positioning king and rook after retracting castling.<br>
As every year, the solver has to check whether there is more than one possible
solution.<br>
<br>
Werner Keym, original. White mates in three moves, Chess960</span></p>
<p class="ydp9a50a156MsoNoSpacing" style="text-align:justify"><span style="font-size:12.0pt;font-family:Arial,sans-serif;mso-fareast-font-family:Times New Roman;color:#1D2228;letter-spacing:-.25pt;mso-fareast-language:DE">r4kr1/p1p5/5K2/8/8/3Q4/8/8
w - - 0 1<br>
<br>
Solution:<br>
First solution</span><span style="font-size:12.0pt;font-family:Arial,sans-serif;letter-spacing:-.2pt">: 1.Qa3+ c5 2.Qxc5+ Ke8 3.Qe7#. Second solution: As Black
just made a move, only one of the two castlings is still possible (so called „partial
retroanalysis“). If ...0-0-0 is still possible, then 1.Qd7! (but not 1.Qh7?
0-0-0!) 1...Rg6+ 2.Kxg6 resp. 1...Rg7 2.Qxg7+ followed by mate. If 1...0-0 is
possible, now 1.Qh7! (1.Qd7? 0-0+!) 1...Rg6+ 2.Qxg6 resp. 1...Rg7 2.Qxg7+. This
second solution consists of two excluding partial solutions.</span></p>
<p class="ydp9a50a156MsoNoSpacing" style="text-align:justify"><span style="font-size:12.0pt;font-family:Arial,sans-serif;mso-fareast-font-family:Times New Roman;color:#1D2228;letter-spacing:-.25pt;mso-fareast-language:DE"><br>
Werner Keym, Problem-Schach-Kunst 2024<br>
White retracts one move and then mates in two moves, Chess 960<br>
7k/8/8/5B2/8/4p3/8/4RRK1 b - - 0 1<br>
<br>
</span><span style="font-size:12.0pt;font-family:Arial,sans-serif;letter-spacing:-.2pt">Solution: retract 0-0 (king to f1, rook to g1) and now 1.0-0-0 (king to
c1, rook to d1) 1...e2 2.Rd8#.<br>
<br>
</span><span style="font-size:12.0pt;font-family:Arial,sans-serif;mso-fareast-font-family:Times New Roman;color:#1D2228;letter-spacing:-.25pt;mso-fareast-language:DE">Bernd Graefrath, Koenig & Turm 2002 (revised version)<br>
</span><span style="font-size:12.0pt;font-family:Arial,sans-serif;mso-fareast-font-family:Times New Roman;color:black;letter-spacing:-.25pt;mso-fareast-language:DE">White
retracts one move and then mates in two moves, Chess 960<br>
</span><span style="font-size:12.0pt;font-family:Arial,sans-serif;mso-fareast-font-family:Times New Roman;color:#1D2228;letter-spacing:-.25pt;mso-fareast-language:DE">8/8/8/8/2P5/6k1/8/2KR3R b - - 0 1<br>
</span><span style="font-size:12.0pt;font-family:Arial,sans-serif;mso-fareast-font-family:Times New Roman;color:black;letter-spacing:-.25pt;mso-fareast-language:DE"><br>
</span><span style="font-size:12.0pt;font-family:Arial,sans-serif;letter-spacing:-.2pt">Two solutions: retract Rd4-d1 and now 1.0-0 (Kg1, Rf1) 1...Kh3 2.Rf3#. As
well as retract 1.0-0-0 (Kf1 and Rd1 unchanged) with 1.Rd4 Kf3 2.Rh3#.<br>
<br>
Regards, Harald Keilhack</span></p></div><br></div></div></div></body></html>