Switch in Time is the name of a book, published
a decade ago,
that describes the "secret" signaling methods of
the top experts -
methods that have been in use for many years but have never
clarified in print. In the book, for the first time, the
codified to make them clear and accessible to all players.
book is now available exclusively as an e-book.
But the e-book is not for sale. You can get by signing up for
the Bridge Today University (BTU) course #190, which introduces
and teaches you the concepts in nine easy lessons.