The ‘Lightner double’ is perfectly named: a bolt out of the blue which strikes fear into your heart. There you are, having bid confidently to slam, when suddenly one of your opponents pulls out the red card. Eek! It’s a Lightner double, which means they want their partner to make an unusual lead: either the doubler has a void and can ruff, or wants dummy’s first-bid suit led (partner needs to work out which). The point is that without the double, the killing lead might never be found.
I used to assume it was a clever made-up name, until I discovered it really was the invention of one Theodore ‘Teddy’ Lightner, an American lawyer who was Ely Culbetson’s favourite partner, and who won the world championships in 1953. His convention is still indispensable today — indeed it came up during the current women’s world championships (taking place in Lyon), in England’s match against the Netherlands — and has helped propel England to the finals:
At one table, Fiona Brown and Sally Brock stopped in 4♠ (Fiona opened 1♠, Sally responded 1NT, South bid 2♠ showing hearts and a minor, and Fiona jumped to 4♠). At the other table, the Dutch EW sniffed the slam… and if they’d stopped in 6♠ it would have been a terrible result for England, but they pushed on to seven, and got struck by Lightner:
It was Nicola Smith (South) who doubled with her diamond void. On any other lead, the grand slam makes, but Catherine Draper (North) duly led a diamond for one down — and a swing of 14 imps.