Chances do Recur

Q 7 6 4
K Q 6
Q 9 4 2
Q 9
5 J 2
J 10 9 8 3 A 7 5 2
10 8 5 ------
A 6 5 4 K J 10 8 7 3 2
A K 10 9 8 3
4
A K J 7 6 3 Opening lead: A of clubs
------ Vul: E-W

SouthWestNorthEast
1 Pass 3 * 4
6 Pass Pass Dbl
All pass *Alerted
However you slice it, opportunities for the Lightner double do recur, and it's almost a cost-free convention. It doesn't eat up any space or wipe out a bid you'd often want to make. Since writing up my first comments, wherein I said that you'll probably first hear that the Lightner double calls for dummy's first bid suit, and subsequently find some sophisticate telling you, No, it calls for an unusual lead. I went on to say that until you get real good, I think you'd do well to stick to the first and very unambiguous take on the Lightner double, "unusual" being a little too vague to give a whole lot of direction. Since then, I came across a professional columnist's statement that the double calls for a lead of "dummy's first bid suit", without any malarky about "unusual," and I felt heartened.
I'd also like to point out that with a void in that first bid suit and an ace, East was employing the double correctly. A void isn't good enough against a six bid. You have to be able to say, "Partner, if you'll lead this suit, I think we can beat the slam." But wait? Suppose declarer's singleton had been a club instead of a heart. Yikes! Then you're not going to beat the contract on a diamond lead, and shift to the A of hearts, now, are you? But no bidding scheme is perfect, which is part of the game. You only go for likelihood, and here, you can see, a diamond lead would have beaten the contract, for a whopping 1300-point swing and that ain't hay. You can live with a few misfires if you get 10 or 15 zingers for every one that misfires, no?