This position was reached in a normal chess game:

                   BLACK
     +---+---+---+---+---+---+---+---+
     | B |///| K |/R/| N |///|   |///|  
     +---+---+---+---+---+---+---+---+
     |/P/| P |///|   |///|   |///|   |  
     +---+---+---+---+---+---+---+---+
     |   |///| Q |/K/|   |/R/|   |///|   
     +---+---+---+---+---+---+---+---+
     |///|   |///|   |///|   |///|   |
     +---+---+---+---+---+---+---+---+
     |   |///|   |///|   |///|   |///|
     +---+---+---+---+---+---+---+---+
     |///|   |///|   |///|   |///|   |
     +---+---+---+---+---+---+---+---+
     |   |///|   |///|   |///|   |///|
     +---+---+---+---+---+---+---+---+
     |///|   |///|   |///|   |///|   |
     +---+---+---+---+---+---+---+---+
                   WHITE

a) Identify the color of each piece.
b) What was the last move?

(In reply to re(2): Opening Moves (part spoiler) by Cory Taylor)

No, it could have simply advanced from A7. The other white pawn behind it could have originally been in the B column or the other way around, who knows? It doesn't matter. A white pawn made it to A8 from A7 and was promoted to Bishop, then another white pawn followed from behind. This game is obviously not conventional. Surely white could have mated long ago with a much more direct strategy but was simply toying with black. Or more probably, this position is a construct for the genesis of a puzzle, but certianly could have been achieved by legal play.

Posted by Eric on 2006-01-10 16:13:06