Games: Crossword puzzlers out for a duck

Some of you reading this article will have been guided across from the crossword puzzle in this week's Ism. Some, I have no doubt, will be angry, some sad, and some perhaps even amused. Others may have hit this piece purely by chance.

The fact is that I have achieved - if "achieved" is the right word - something quite unusual, and have been invited by my long-suffering crossword editor, Louise Levene, to give an account of myself. In puzzle 149, published on 18 April in Ism, I invited solvers to fill in some squares with clashing letters "to accord with the shape they make", adding that "a final mark should be added at an appropriate intersection of two grid lines". The shape (see Ism) looked like a K knocked over. I assumed that readers would interpret it as a (pi) and work out (perhaps following the hint in the puzzle's title "More or Less") the numerical differences between the clashing letters.

Thus, at the bottom of the pi the second I of IMAGINE in 26 down is three away from the second L of LILY at 41 across, so "3" is entered. Progressing up the leg of the pi, we get 3141, then 592... along the top and 7932 down the bottom leg. When you add the decimal point after the opening digit, you get 3.141592... the value of . Clever stuff? Obviously too clever for all eight or nine hundred entrants.

Looking back, I can see that the shape of the pi is a bit inaccurate, and perhaps in my day job as a maths editor I am used to seeing too many hand-written approximations to this transcendental wonder. But surely the shape wasn't that bad, and a few mathematicians would have seen what I was driving at? Alas, I miscalculated.

There has long been a tradition of providing impossible or near-impossible crosswords. Two Listener puzzles spring to mind: in one crossword by "Afrit" in the Thirties or Forties, the publication expressed regret that none of its readers connected "Lombardy" and "Man of Words" with The Cardinal's Snuff Box at 28 across - a connection which some of us still fail to make; and about 20 years ago there was a puzzle entitled "Lip Service" by Leon, which involved playing a game of solitaire and spelling out the inscription on the Blarney Stone.

Afrit was a master working out the rules of a new game; Leon was probably too clever for his own good. So where does that place Duck? I'm in the Leon camp, though I suspect Leon knew what he was doing. I guess that, despite over 30 years of setting, I didn't. I am as dumbfounded by the zero correct entries as the hapless solvers who failed to recognise the malformed mathematical symbol. But my feelings, to be honest, are mixed: I'm tempted to be excited at having fooled everyone, but reckon I should feel guilty at having spoiled everyone's fun.

Only two more things need to be said. One is that we need to explore the new and strange in crosswords to keep the game alive; the other is that no one should ever set out deliberately to produce a puzzle that will stump all the solvers. On that charge I plead innocent, so my apology to Ism enthusiasts has some qualification. For most of the time, the setter must expect to be a gracious loser in a battle of wits in a contest that has a fair set of rules and conventions. That is how the battle is normally conducted in the Ism puzzle, and indeed all the puzzles in The Independent and Independent on Sunday.

Don Manley contributes as 'Duck' to 'Ism'. His less-than-impossible puzzles appear weekly in the 'Independent on Sunday', in the guise of Quixote.