As of December 1, 2000, I will be leaving Bell Labs to pursue flight instructing full time.
I do not know what will happen to this site after that.
In particular, the chess endgames could disappear at any time.

pieces max zug freq
BB-NN co co co
BBB-B c none c
BBB-N c none c
BBB-R co co co
BBN-B ca    co    cs ca    co    cs ca    co    cs
BBN-N cs    co cs cs    co
BBN-Q co    cs co co    cs
BBN-R co    cs co    cs co    cs
BN-NN c c c
BNN-B cs    co cs    co cs    co
BNN-N c c c
BNN-R c c c
NN-NN c c c
NNN-B c c c
NNN-N c c c
NNN-R c c c
Q-BBB ca    co ca    co ca    co
Q-BBN cs    co cs    co cs    co
Q-BNN c c c
Q-NNN c c c
QB-QB cs    co co    cs cs    co
QB-QN c c c
QB-QR c c c
QB-RB co    cs co    cs co    cs
QB-RN c c c
QB-RR c c c
QN-QB c c c
QN-QN c c c
QN-QR c c c
QN-RB c c c
QN-RN c c c
QN-RR c c c
QNN-Q c c c
QQ-QQ co co co
QQ-QR c c c
QQ-RB c none c
QR-QB c c c
QR-QN c c c
QR-QR c c c
QR-RB c c c
QR-RR c c c
RB-BB cs    co    ca cs    co    ca cs    co    ca
RB-BN co    cs co    cs co    cs
RB-NN c c c
RB-RB co    cs cs    co co    cs
RB-RN c c c
RBB-Q co    cs co    cs co    cs
RBB-R cs    co cs    co cs    co
RBN-Q c c c
RN-BB cs    co cs    co cs    co
RN-BN c c c
RN-NN m    c m    c m    c
RN-RB c c c
RN-RN c c c
RNN-Q c c c
RR-BB co    cs cs    co co    cs
RR-BN c c c
RR-NN c c c
RR-RB c c c
RR-RN c c c
RR-RR c c c
RRB-Q c c c
RRN-Q c c c
RRR-Q c c c

c -- maximal starting position, play to capture or mate
m -- maximal starting position, play to mate
o -- opposite colored bishops (w-b, b-w // wb-w, wb-b // w-wb, b-wb // wwb wbb)
s -- same colored bishops (w-w, b-b // ww-b, bb-w // w-bb, b-ww)
a -- all bishops same color (ww-w, bb-b // w-ww, b-bb // www, bbb)