Dubious Logic

The Lightner Double

Opponents are trying to claw back a deficit in the last quarter of the match when this potentially crucial deal arrives. With neither vulnerable, you are South and have to lead against a doubled grand slam from these cards:

• Q74
• 62
• QJ8752
• J8

North's double is a Lightner Slam Double, one of the few almost universal bridge conventions, calling for an unusual lead. In his classic book, Why You Lose at Bridge, SJ Simon introduced the idea as an example of mathematically sound tactics. Though written 70 years ago this year, in chapter one Simon identifies three principles as pertinent then as they are now:

1. How much can my bid or play gain?
2. How much can it lose?
3. What are its chances of success?

Simon proves that doubling a slam with two aces is foolish; the upside is tiny (an extra 50/100) the downsides worse (they have a void, they redouble). But doubling a slam to help partner find the lead to defeat it - that is great bargain. The downside is the same but now relatively small compared to the bonanza of beating a slam that would otherwise have made.

Hence American expert Theodore Lightner's double; it deters an expected lead in favour of an unusual one. As Simon says, "… if your partner has bid hearts and subsequently doubles six spades, the one lead he does not want is hearts. He is shrieking for a club or diamond (probably he can ruff one of those suits) …". And if partner has not bid? Look to the opponents' suits, usually dummy's where there is positional advantage.

But, as the years have progressed, Lightner doubles have become more 'unusual' and less codified, meaning more thinking for opening leader. Enough stalling do you have a lead yet?

As you can see, you have to lead a spade – or, ironically that standby against grand slams, a trump. Everyone I've polled has led a diamond as did the South at the table. Declarer took four tricks in the minors and cross-ruffed for the rest; 7X=, +1770.

Should South have worked this out? Possibly; North hadn't doubled six hearts which he surely would had he been void of diamonds, trusting in the ruff for one trick and another outside to beat six – that much is the 'Lightner equation'. Spades is surely the unusual suit in which the defence may have a single winner (in North's view). At the other table against six hearts South again led a diamond and declarer took the same 13 tricks. Fortunately for South they had more than enough in the bag on other boards and increased their lead to take the Scottish Cup Final.

Published Saturday 7.Feb.2015