Solving the Mystery of the Redouble - James Marsh Sternberg MD (Dr J) - Bog

More often than any other calls in bridge, redoubles produce confusion. When they do, the resulting disasters are more catastrophic than any others.
Many doubles originally treated as penalty have been supplanted by conventional doubles. So also many "business" redoubles, originally used to quadruple the stakes, have been diverted to other uses.
In this book we shall show you how to tell the different kinds of redoubles apart, and what agreements to make with partners to avoid confusion and its tragic consequences.
An understanding of the use of these redoubles should be an essential part of your bidding system to improve your contracts and your results.