Originally posted by geepamoogle
[fen]2BR3N/3pk3/4p3/4K3/8/8/8/8 w - -[/fen]
Could some of you retrograde experts confirm if this position is even possible to reach, and if so a possible set of the previous 2-3 moves for it?
I suspect the position is an impossible one, but even if it isn't, it would probably require black to make completely unlikely blunders like not capturing unprotected pieces at no cost.
This position is trivially legal. Black has several possible last moves, including:
-1...Ke8(x)e7 [preceded by -2.c7xd8=R]
-1...Kf7(x)e7 [preceded by -2.h7-h8=N, -2.g7xh8=N, or -2.Ng6-h8]
-1...Kf8(x)e7 [preceded by -2.c7xd8=R]
-1...f7xe6 [preceded by just about any move/capture by any white piece!]
And so what if the game's history contains blunders, however unlikely? That is of no consequence. If there were no previous blunders, there would be no forced mate. And the line between an unlikely blunder and a likely one is far more blurry than you might think.