Retro World IV: The Pre-existence of Being By Jeff Coakley Retrograde analysis is a form of logical reasoning in which past events are deduced from details in the present situation. This column features six last move problems. The task is to determine the move or moves which led to the given position. Before beginning our investigations, here are a few notes from The Chess Detective's Handbook, the classic work by resident Cafe sleuth Harmonius Hound. When answering the question "What was the last move?", be as precise as possible. A complete description of a move includes the square a piece moved from, whether a capture was made, and if so, what type of piece was … [Read more...]

by Jeff Coakley This column presents ten “Halloween problems”. They are called that because the pieces are wearing disguises. We know where they stand, but we don’t know their colour. Part of the solver’s task is to figure out which pieces are white and which are black.   The normal name for this type of puzzle is a colouring problem. The earliest compositions date from the 1960s. Here is a fairly basic example to get the party started. Halloween 01 Colour the pieces so that White has mate in one. As you can see, all the pieces in the diagram are shown as white. The object of the puzzle is to determine which pieces are actually black. It almost goes without … [Read more...]