Listen With Others

Listener No 4673, Chessboard Carte Blanche: A Setter’s Blog by Hedgehog

Posted by Listen With Others on 12 Sep 2021

I always enjoy exploring number patterns and relationships and also challenging myself to set a puzzle with a new twist or idea. This pair of puzzles fulfilled both so was a pleasure to set.

The first puzzle, Chessboard, was a “normal” crossword and appeared in Crossnumbers Quarterly last year and involved squares and cubes. After I had set it, I thought whether there any more mileage in the chessboard idea as 8×8 is a very convenient size of grid.

A carte blanche crossword came to mind quickly but I spent some time thinking over the options. Time spent here can avoid wasting a lot of time later. A carte blanche involves a fair amount of cold solving but the jigsaw element is easier to do with 26 letters than with 10 numbers. I was not attempting to replicate a word carte blanche but wanted to make sure there was a challenge in both the cold solving and the jigsaw. To do a puzzle where the jigsaw element could start early would probably require some 8-digit answers and maybe some other 6 or longer entries that could be cold solved. This looked a bit daunting so I settled on a grid with shorter length entries with the expectation that solvers would be able to cold solve most but not all the clues. My first (and final) grid had 1 across starting in the second square and containing two unchecked cells as I wanted to make the jigsaw part more of a challenge and I was already planning that it would be a clue that could not be cold solved. The grid fill started with the Fibonacci number and the cube with 729+729=1458 as I felt it was important to give solvers a good start. My grid fill then followed the solution path until I had a few clues left that needed feedback from the grid. My final act was to put in the preamble that bars need not be entered as one of my pet hates is the unnecessary entry of bars in puzzles.

When I submitted the puzzle, I was reasonably happy except that the “crossword” element of the puzzle only came in when solving the last few clues. This was noted by Roger but he was happy to publish it with a few improvements to my preamble. One or two solvers also commented on this but I was pleased that so many enjoyed the puzzle. I’d like to thanks all the solvers that took the time to comment.