chess-The Oxford Companion to Chess - First Edition by David Hooper & Kenneth Whyld

76 CONJUGATE SOUARES
A-r, in thn case representine low asNanss, b1
orb3 = h6orb8. (Two unmarked pairs, c7=e7and
c8=e8, are noi.elevant to theplay.) While wanls
10 play K d4 threatening e4 c5,orK-e3threal'
ening K i4, and eithcr would Mn unless Bl.c[
muld rcply immediately... KI6z or... Kg5z
rcspcdively. Thtrs the pans G=g and I(:[ arc
identified. By exlension oulwards all the otner
pairs can be found. For cxanple, if White plays
Kd3 gaining a@ess to both d4 d e3, Black needs
to reply . . . Kg6z to gain acess to 16 and c5; ttus
(L3=g6. Bla.k to play oulddrawby L . . KgTor
I . . Kh7 onrinuing 2 Kb2 Kg8z or Kh6z, or
2 Kb1 Kg6z. Holdins the delensive (nregulao
opposnion. hc can alNays Place whitc in ztrgflang.
White ro play *iN in the same way thal he
wonld win if he held the regnlar opposition: he
holds Bl.ck in zuczwang uniil he can oudank
successfully. _fhc key is 1 Kblz. Two variations
follow: 1 . . Kg7 2 Kciz KS6 3 Kdlz Kg5 4
K.2 (ouina.king) 4...Kn6 5Kd22(h5 6Kc3
(oudanrjng) 6...Kgs 7 Kc4 (oudantins) 7
...Kg6 8Kd3zi 1...KhS 2Kb2z(C8 3(b3z
Kh8 a Kc4 (outflanking) 4...K97 5Kc3zrr
6 Kd2 (outflankina) 6... Kf6 7 Ke2
(oudanking) 7...Kg6 8 Kd3z.
I-ocockt study, the frrst ot its kind, made no
immediate inpact. hsER noted it, and in 1901,
airer winning the world championship a.d a few
naior loumaments, he constructed a oniugate
sqrare study shich attracted wide inlerest Many
such sludies folloped. In the 192G and 1930s
attempts were nade to establkh a conprehemive
classilication oI rhe nany pafterns thal are Po$ible
in conjqatc square positions. Tle results Nere
unconvincing. For exanPle. rhe Li.ock stndy is
supposed to sbow the eighr-square synen'
because tbe squarcs .4d4,c3,d3,e3,c2,d2, and e2
arc pairedmi.roFlashion witheighl squarcs on the
other side of the diagonal axh h2 b8. This is a.-
interestina obseNalion, but il accounls lor lewer
than halfthc conjusate pairs. To undestand a se1
of such pairs those that occur when lhe kings are
close roge ther should be di scovc red , a.d Lon this
slarting poinl other pais can be derived.
tr&, xa
7e % 7"&.
tw vg&
%%w
'7& Tlgr
A studv b; MANDTR. wii',, s chochzeitunp. Ts24,
a rare;x;mple oI dnjugate squares ocuPied by
picces other than kings. The kniSht and bishop
6ghl a duel while rhe kin8s and pasns sta.d by. For
Black's knight there are 6ve key dark squares, b2
andc5 which gi,c checkmale, e5,95, and i2 when
nate cannot be preve.ted. The approach to these
is by way of 15 light squares, b?, d7, tf , h7, e6, 96,
c,l. e,l,94, b3, d3. fJ, h3, dl, or hl, and the bishop
musl prevent lhe knight lron reaching any on. oi
them. ztrgnangs anse becalse the bishop may be
ablc io defend lrof onlyone squa.e, e.g. with Nl6
wlire needs his bishop on f5, and he annot lole
the nove snouH ii be his turn to play.Inherently,
the posirio. cont.i6 36 zugzsangs. Thee are
irrelevant to the solution (Nd8:Bd5. Nl8=8f5,
Na5-Bd5) and 1wo a.e umecessary: whitc may
rcpl! r..
Ng7 byBf5 nol Bdlz. and may repl) to
Nal hy plaJants hi5 bi\h.p to the , 88 didBona)
instead oI Bdtz. For , posnions ot the knighl
White can detend only by setting up zugaangs:
Nc8=8I, or Bt:
Ng8=8g6 or Bg4
Ne7=Bh5
Nd6=Bd5
Nf6:Bf5
Nd5=88'1
Nf5=BB
Nd4:Bd5
NI4-B15
Nc3=Be2
Ng3=Bd5
Nc2=BB or B.4
Nd2=Bd5
Ne2=Be6
NC2=Bg4
Ng1=Bg4
Nfl=BB
While to play draws by I Bh5z alter which he can
always hold Black in zu8dang.
The inlomation about conjugate squares .on
rained io standard endgane books is sufficient for
nost pra.tical puposes. Among speoalisl boots
ire Rinaldo Bianchetti. Co"ri buto alla Teoria del
Finole di Soli Pedoni (1,925)t DU.H&. and Il8lr
sr^Dr, L'Oppasition et les cdes coniuge^ sont
ftconcilii* (1932); aad Waltet Bibt. Opposition
u Krnbche Fel.l.t in Boumendspiet (1936).
CONNECTED PAlvN, a pawn thal can guard or be
gudded by a pawn o. a. adjoining nle. theternis
tsenerall, used i0 rhepluralL.dehne a groupuflNo
or more sucb pawn(. such a Eroup may include
doubledpawns: for example, after 1 e4 c6 2 d,{