Prism signals

(described by Luis Argerich)

I've received some emails asking about prism signals, here is our method:

Introduction: In every bridge hand you have one even suit and three odd suits or one odd suit and three even suits. Voids are even. If you don't realize this take a couple of minutes, for example 4333 (3 odd, one even).

Concept: Using dummy as a "prism" partner can "reflect" declarer's hand if by signalling wisely. The prism signals use primarily trumps as the signalling suit, in NT the dummy's best suit or declarer's obvious long suit is used as "trumps" The "singular" suit is the one wich has different parity than the others (in 4333) the 4 card suit is the singular one, the others are all odd.

The signals:
You signal to partner whether your "singular" suit is odd or even AND (if you can) which is your singular suit. With 2 trumps you can only signal parity; with 3 or more you can signal parity and suit if possible (Hxx is considered 2 cards in trumps in this method for obvious reasons...)

Then with 2 trumps:
Hi-Lo : Mi singular suit is even.
Lo-Hi : Mi singular suit is odd.

With 3 trumps: (HML)
H-M-L : Singular even and is the lowest suit.
H-L-M : Singular even and is the middle suit.
M-L-H : Singular even and is the highest suit.
M-H-L : Singular odd and is the lowest suit.
L-H-M : Singular odd and is the middle suit.
L-M-H : Singular odd and is the lowest suit.

As you can see, the Hi-Lo Lo-Hi signals parity and the third card, if expendable, is used to signal the rank of the "singular" suit.

With two trumps we agree that the next cheap card played shows which is the singular suit.

How to use the signals:

It's confusing at first but works amazingly, believe me. You get used to it and you are a "tiger". You have to know how to clasify dummy (the prism). The prism is calculated from your cards and dummy as following:
Each prism suit number is 13-(Number of cards of that suit in your hand+Number of cards of that suit in dummy).

Example:
You: 4-4-2-3
Dummy: 3-3-3-4
Prism: 13-7,13-7,13-5,13-7= 6-6-8-6
Then we classify:
Even Prism: All 4 numbers are even
Odd Prism : All 4 numbers are odd
So in the example we have an even prism but the prism could be for example: 8-3-7-8
Then we have a complex prism:
Complex prism : 2 odd numbers and 2 even numbers.

Knowing that and the following rules, you know everything:

RULE 1: (EVEN PRISMS): Declarer's singular suit is the same suit as partner, and the parity of that suits is equal.

RULE 2: (ODD PRISMS): Declarer's singular suit is the same suit as partner, and the parity of that suit differs.

RULE 3: (COMPLEX PRISMS): Delcarer's singular suit is the suit with the same parity as declarer in the prism.

(Example 8-3-7-8
if partner's singular is spades declarer's is clubs
if partner's singular is hearts declarer's is diamonds)
If the singular couple is odd in the prism, the parity of the suits is EQUAL. If the singular couple is even in the prism, the parity of the suits DIFFERS.

Example (urgent:)
Dummy: 5-3-2-3
You : 0-7-4-2
Prism: 8-3-7-8,
Partner signals singular suit is spades and even...
Then: You know that in a complex prism if partner has singularity in spades declarer should have it in clubs, and since spades is "8" in the prism the parity of the suits differs. So declarer singular suit is clubs and it's odd.

The bidding was:
YouNorthEastSouth
4s
5h6sdoublep
pp
Dummy:
K9742
97
Q5
QT9
You:
-
KQJxxxx
AT53
A8

You led the King of hearts to declarer's Ace, then declarer draws trump (parter playing hi-lo) and then plays club to the Queen and a club to your Ace partner signalling odd clubs. You have to know if you can cash the dA or the hQ!!! NOW!!! Knowing the 8-3-7-8 prism, you know partner's singular is spades so declarer's singular is clubs, partner's singular is even so declarer's is odd. Thus declarer has 1,3 or 5 clubs, since he has 6 spades and the other suits are odd. Declarer is 6205. No other distribution is possible; so you show declarer the hQ and say confindently "1 down..."

I hope you like the method...

Luis. 1