Abstract. We describe the generation of a library of eyes surrounded by only one chain which we call monolithic eyes. Apart from applying the library in the life-and-death program GoToots it also can be used as a source for the study of unusual positions in Go as done in the second half of the paper.

Introduction

In using principles of combinatorial game theory it has been discussed in the literature how in the game of Go one can assign values to eyes in order to decide whether a position lives unconditionally, simply by adding these values and checking whether or not their sum reaches the value of two (see Landman). These concepts are applied in computer Go programs (as in) and a computer generated library of eye shapes is available from Dave Dyer.

In this contribution we describe the generation of a library of eyes surrounded by only one chain which we call monolithic eyes. Compared to Dyer's library our database has a number of extensions: an evaluation of the number of ko threats needed to live or to kill the eye, the consideration of a larger number of external liberties and of an extra attached eye, larger eye sizes, the determination of all winning moves and others.

In the following section we describe a procedure to bring any set of empty or occupied points into a unique position by using shifts and symmetries of the board.