**FOREWORDS**

__From the foreword to the first edition in Polish ( June 1976)__

**The area of defensive signals in bridge is still a relatively unexplored
one. In choosing one method rather than another we are usually influenced by
the current fashion, years of habit and other similarly irrational reasons.
This book is an attempt to create a theory of defensive signals, to
examine known methods and to construct
better ones. In order to do this the author has used a method of statistical
analysis which appeared first in the article "Distributional Leads"
("Brydz” 9/1974).**

__Foreword to the second edition in Polish (March 1979)__

**The first edition surprised many readers who expected to find he answers
to such problems as "What do you lead against 3NT after such–and–such a
sequence", "When to try for a trump promotion", etc. Some
readers thought that, as I had decided to publish my own discoveries in the
field of defence, I should have lmited myself to a short pamphlet rather than a
comprehensive book. So I want to make it clear that the aim of this book is
only to answer the question "Why should I defend this way?". Any
worthwhile discovery can be made by accident: "We've been playing this for
a while now; let's try that" (and next month we'll**

**play so–and–so). One of the methods you try may well be the best
available; but what of it if you don't realize it and abandon it after the
first disaster in favour of tried and trusted methods.**

**So it is not enough to make a discovery; you also have to prove that it
is a good one. The way to do this is not to produce examples where your method
works – there will also be examples where it doesn't work – but to investigate it statistically. Results
in practice are certainly not the right criterion, and on this point I am in
agreement with Zachary Lichter:**

**"The desire to find a unique solution to a problem is not a
function of stupidity, the strength of which depends on the fact that it can
ccept any theory, even a demonstrably bad one, provided good practical results
can be obtained using it."**

**In the second edition, certain areas were examined in more detail, and
some new ideas were introduced (evaluation of signals, permutations of small cards, SEQUEL, problem 5 – 6,
expressing the efficiency of a system as a percentage). The name
"Combination Leads" (or "Mixed Leads") was changed to
COMBINE (the adjective mixed being reserved solely for the Mixed Signal
and MM). In the Combine System itself
the leads from Q 10 9 and Hxxxxx were changed.**

__From foreword to the third edition in Polish (1980)__

**An addition to the chapter dealing with permutations of small cards is
Marek Dryanski's idea about minimizing the rank of the first small card played.
Also, the relative efficiency of the signals L Q M has been corrected (see
'Evaluation of signals') as well as a few small
errors in the test tables. This has the effect of insignificantly
changing the percentage efficiency of some small–card systems, but has little
bearing on the final conclusions.**

**In the 4th edition the author hopes to achieve totally error–free
results with the aid of a computer.**

__Review in "The Bridge World"
(May 1985)__** **

**"System in Defence" is about conventional methods for leading
to a trick. It is for the theoretical–minded. Make that v e r y theoretical–minded,
because even though the book's conclusions can be applied in practical play,
only theorists have any chance of enjoing the reading.**

**The nain ideas of this book are, first, to introduce a scientific method
for comparing the effectiveness of different lead conventions, and, second, to
suggest some new methods that seem (under the criteria presented) to offer
greater effectivenessthan those currently in use. For example, one interesting
idea "mixed signal", where you signal neither length nor quality but
a mixture of the two.**

**The author makes some assumptions that will not be acceptable to
everyone (eg that using the same method against notrump and suit is an
overriding priority), so few will agree with all his conclusions. Regardless ,
the proposed general approach, and some of the specific methods, are important.
We believe this is an important contribution to the theoretical literature.**