II.   REFRACTION

Helge Vinje in his New Ideas in Defensive Play in Bridge described the hand pattern signal -ordered spot card play in the trump suit that communicates single suit parity.

Prism Signals incorporates the hand pattern signal and develops the underlying theory to support an extensive battery of signals. Playing Vinje hand pattern signals, East holds:

9

6

5

2

5

2

9

8

4

J

8

6

4

and hears this auction:

West	North	East	South
---	---	---	1
Dbl	1N	Pass	4
Pass	Pass	Pass

While West searches for an opening lead, East notes his odd single suit, diamonds. Hand pattern signalers play a low trump spot followed by a high one to send the message I have an odd single suit.

Examine the problem from West's point of view:

West leads the diamond king, continues with the ace, and South wins the third round with the queen -East follows. Declarer plays ace and a trump. East signals low-high with the deuce and five.

    West wins and must find a continuation to ensure one trick in this position:

East's spots send the message I have an odd single suit. East started with three diamonds. Quick, what is declarer's hand pattern?

Now suppose that, rather than I have an odd single suit, West receives the message Declarer is even only in hearts.

Declarer started with six hearts. The index of declarer's hand pattern is six . The path to declarer's hand pattern is direct. Two such patterns exist: 6-3-3-1 and 6-5-1-1. The opening salvo -three rounds of diamonds- rules out 6-5-1-1. Declarer's hand pattern is 6-3-3-1. The club ace is cash in the bank. Down one.

The full deal:

A defender who receives a hand pattern signal uses a prism to refract the light partner sheds on his own hand, bending it to beam instead upon declarer's hand.

The prism transforms information about the parity and identity of defender's single suit into a description of declarer's hand pattern...instantaneously.

Consider again the deal above. Same auction to four hearts, but now East holds:

9

6

5

5

2

9

8

4

J

8

6

4

2

East notes his even single suit, hearts, and play proceeds: three rounds of diamonds, ace and a heart. East follows high-low in trump to send the message...

West, in with the heart king, needs to score the club ace or the spade queen to defeat four hearts in this position.

Declarer started with three diamonds, so his hand pattern index is three. The index chart lists 4-4-3-2  (ruled out by the auction)  6-3-2-2 and 6-4-3-0. West must consider two distributions: 2=6=3=2 and 4=6=3=0.

The defense effective against both distributions is not easy to find. However, the well defined distributional parameters grant narrow focus to the search.

West is alive to the danger of attempting to cash the club ace. Declarer may hold none. West is also confident that if declarer does hold clubs, he has two.

The full deals:

or

A club void must be accompanied by four spades. One discard on a club honor cannot help declarer. A low club exit is the effective defense against both index three hand patterns. (Note: A low club exit works here also, but cashing seems simpler.)

If a peek is worth two finesses, is a prism worth a compound of squeezes?