(;
GM[1]FF[4]VW[]AP[Many Faces of Go:11.0]
SZ[13]
HA[0]
ST[1]
PB[B.K.Przybyla]
PW[R.Granville]
DT[1984]
PC[London]
KM[5.5]
RU[Chinese]
RE[B+15.5]
EV[Acornsoft Go Tournament]
RO[3]
C[Comments in square brackets are from the official game commentary, \
by Charles Matthews.

Comments in angle brackets are from an article in the British \
Go Journal, by Matthew Macfadyen.]
;B[ck];W[jk];B[kc];W[cd];B[gk];W[ek]
C[[ After opening palys from the two programs in their preferred \
styles, White invades deeply and starts a fight.  In fact 6 was \
chosen by the program because it matches known patterns (with1 \
and 5). \]]
LB[ck:1][jk:2][kc:3][cd:4][gk:5][ek:6]
;B[ej];W[dj]
;B[dk];W[el]
C[[ These are reasonable tactical plays, though 10 is a little \
dangerous. \]]
LB[dk:9][dj:8][ej:7]
;B[di];W[dl];B[cl];W[fj];B[ei];W[fk]
C[[ The strength of the Black program is shown in its calculation \
that the isolated White stone cannot escape. \]]
TR[dj]
;B[gl]
C[< Black 17 creates a very tense situation - neither program explicitly \
recognises eyes, so one of the groups on the side is likely to \
die. >]
;W[cg]
C[< White has no idea that his group is in trouble.  >]

;B[gi]
C[[ This is a play which impresses even if the program had reasons \
for it at which a Go player might smile.  The White group is \
under pressure, but can escape with correct play. \]

< Przybyla's program looks for ways in which groups can extend \
towards the centre, and finds 19 because it was the only way \
for white to extend. Having played here, however, it loses interest \
until the group is down to 2 or 3 liberties.  >]
;W[fi];B[fh];W[eh];B[cj]
C[[ Black 23 is played because the ladder to capture no longer \
works after 22.  It would be better at C5 for this purpose; in \
fact for deeper tactical reasons missed by the program the White \
stone still could not escape. \]

< He knows about ladders, and spots that white 8 can't be killed \
in one any more.  >]
LB[eh:22]
;W[gj];B[gh];W[dh]
C[[ White misses the key move to escape (H4); the program was reasoning \
that with 4 liberties the group was not under threat. \]]
TR[dl][el][ek][fk][fj][fi][gj]
;B[hj];W[eg]
C[[ This is strange play from White. \]]

;B[ch]
C[< Lucky. As long as black 31 has not been played, the three stones \
7, 11 and 15 have only two liberties and Black will not 'see' \
that the big white group has only three. After 31, though, he \
can 'see' white's danger, and adds another stone at 33, so that \
he can prove that white is dead.  >]
;W[bh];B[ci];W[fg];B[fl];W[bi];B[bj];W[hi];B[ii]
(;W[hk];B[hh];W[hl];B[dm];W[gm];B[em]
C[< Having played 33, Black can handle the fight up to 43. The \
game was by no means over after 43, but Black's advantage was \
clear.  >]
LB[hk:38][ii:37][hh:39][bj:35][bi:34][fl:33][hl:40][gm:42][dm:41]
;W[ki]
C[[ The Black program has proved convincingly that it can count \
liberties!  After White's last good play to secure the corner \
the game is still close: White has lost some stones but has built \
territory on both sides. \]]
;B[ik];W[il]
;B[fm];W[hm];B[ij];W[jl];B[jj];W[kj]
C[[ Poor play from Black - White might safely have ignored 47. \
\]]
LB[jj:51][ik:45][il:46][hm:48][fm:47][ij:49][jl:50]
;B[gc];W[ec];B[ic]
(;W[kk]
C[[ This deserves to be called a losing play.  The White program \
could capture a Black cutting stone at L3 (that is, if Black \
did not play there, White would play correctly), but the program \
cannot look the one step further to see that this cutting point \
is therefore defended.  The Black program would do the extra \
step in such a situation, and gain a play. \]

The original commentary text has "K3" not "L3".  The diagrams \
used were labelled ABCDEFGHIJKLM.

< White 56 is more or less the losing move. Both of these programs \
explicitly recognise ladders, and neither would cut at 56, but \
Richard's program does not make the one extra step needed to \
avoid protecting against it.  >]
;B[kg];W[ke]
C[[ The same invasion as on the lower side, but Black is strong \
in this corner; the fight is short and sharp. \]]
;B[je];W[jf];B[kf];W[if];B[le];W[ld]
C[< White 64 is an example of a blunder several of the programs \
made - trying to make good shape from dead stones. The shape \
of 58, 60 and 64 is good, but white is not 'strong enough' to \
use it properly. This is one of the trickier problems with using \
simple minded definitions of good shape.  >]
LB[jf:60][ke:58]

;B[kd];W[lc];B[lb];W[me];B[mb]
C[[ White has been thrashing around; the program has been concerned \
with making good local patterns without reference to the general \
context of hopelessness of this part of the board. \]]
;W[ie];B[lf]
C[< 71 is a wasted move, but many of the programs would have wasted \
two moves by capturing 64 and 66 completely. >]
LB[lc:66][ld:64]
;W[bg]
C[[ Another unnecessary connection, but this does cover some local \
weaknesses. \]]
;B[jg];W[ee]
;B[gg];W[ff];B[gf];W[aj];B[id];W[he];B[hd]
C[[ Black's last 5 plays have been very clumsy; the program has \
little sense of how to cut off stones (in fact it was merely \
filling liberties here, with each one being considered of equal \
importance). \]]
LB[jg:73][ee:74][gg:75][ff:76][gf:77][aj:78][id:79][he:80]
;W[ge];B[ig];W[ak]
;B[bl];W[al];B[fb]
C[[ This has been the largest endgame play for some time.  From \
now on, Black redeems its earlier lacklustre efforts by play \
which is essentially faultless;  the game, which had become quite \
close, turns into a clear victory. \]

< Black 87 has been the biggest point for some time - if white \
had taken this point instead of 86 he might still have had a \
chance. From here until 105, black's yose is almost perfect. \
>]
;W[bm];B[eb];W[dc];B[db];W[cb];B[lh];W[li]
;B[ca];W[ba];B[da];W[bb];B[mi];W[mj];B[mh];W[fc];B[ji];W[fd]
;B[kh];W[gb];B[hb];W[fa];B[ga];W[mk];B[cm];W[am];B[gd];W[mf]
C[[ If White had earlier occupied L6 this would have tested the \
analysis of both programs (the threat being M7).  Sadly we missed \
the chance of a final drama. \]

(original record has K6, L7)]

;B[bk];W[ai];B[hg]
C[[ Amazingly, this is just as good as the "obvious" H8 (recall \
that Chinese-style rules were in force). \]]
;W[be];B[hf];W[fe]
C[[ Most human players would now agree that the game is over, and \
proceed with the counting.  The programs played out the game \
in their respective styles, until we had a fitting ending of \
respective passes, without outside intervention.  Black had the \
more sophisticated approach, removing the five dead stones inside \
its area by filling liberties, and then passing.  White's plan \
was to keep playing until all the vacant areas on the board were \
of one or two points only.  This led to White incursions into \
the Black domains; these were patiently captured by Black, who \
then returned to passing mode.  For reference, these final moves \
were \]]
;B[ea];W[cf];B[mc];W[df]
;B[md];W[bc];B[mg];W[ll];B[tt];W[jb];B[jc];W[ib];B[kb];W[ka]
;B[ia];W[la];B[ma];W[km];B[ja];W[af];B[tt];W[ad];B[tt];W[mm]
;B[tt];W[de];B[tt];W[ab];B[tt];W[fj];B[fk];W[el];B[gj];W[tt]
;B[fi];W[tt];B[dl];W[tt];B[ek];W[tt];B[tt]
C[[ Black is 21 points ahead in territory on the board; after counting \
komi Black wins by 15.5 points.

A notable feature of the game was that White did not capture \
a single Black piece.  In Go one can lose many of the battles \
and yet win the war - in fact many strong players adopt strategies \
of this kind.  The fact that the game remained close until the \
endgame despite White's early loss points up the superiority \
of White's territorial play; but finally the Black program showed \
strength in its tight endgame, and wrapped up the game.  The \
present Go programs look very poor if they lose their sense of \
direction, and so appear rather weaker than the par level of \
20 kyu which seems to be the actual state of the art; this final \
showed that they are also capable of producing passages of play \
which are a fair imitation of an able beginner. \]

< Note that the tournament was played on the basis of Chinese \
counting, so that the many extra stones White played inside his \
own territory at the end cost no points, and the stones Black \
played to capture White's dead stones were necessary according \
to the rules.  >]
)
(;W[kg];B[kk];W[lk];B[kl];W[ll];B[km];W[lm];B[jm];W[im]))
(;W[hh];B[gg]))
