Go strategytactics
The gameGo has simple rulescan be learned very quickly, but players will soon seek guidance onstrategytactics ofgame.
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2 LifeDeath 3 HighLow 4 ThicknessLightness 5 AttackDefense 6 TerritoryInfluence 7 Ko Fighting 8 SenteGote 9 Opening (fuseki) 10 Endgame (yose) |
ConnectionSeparation
Stones onboardeasierdefendgroups; connectinggroupstones makeshardercapture, sinceopponent would needcover allliberties ofgroup, capturinggroup completely, rather than capturing single stones. A good tacticemploy, then, isattemptdivideopponent into separate groups, while keeping one's own stones connected. (Note that when Black starts withlarge numberhandicap moves, his stonesmainly usefulthis purpose;White player's stonesthreatened immediatelyseparation, while Black has many potential connectionsbegin with.)
LifeDeath
A key concept intacticsGo, though not part ofrules, isclassificationgroupsstones into alive, dead or unsettled.
Atend ofgame, groups that cannot avoid being captured during normal playremoved as captures. These stonesdead. Groups can reach this state much earlier during play;groupstones can quickly run outoptionsfurther playsave itfruitless. Similarly, further playkill suchgroupoftenno benefit (unless requiredgain libertiesan own group), since ifremains onboard atend ofgame itcaptured anyway. Thus groups can be considered "dead asstand", or just dead, by both sides duringcourse ofgame.
Groups enclosing an area completely can be harderkill. Normally, whenplay causes an area completely enclosed byopponentbecome filled,group fillingareacaptured sincehas no remaining liberties (suchplaycalled "suicide",obvious reasons). Only iflast play insidearea would killenclosing group, thus freeing one or more liberties forgroup that filledspace, canplay be considered. This can only be achieved ifliberties onoutside ofenclosing group have been covered first. Thus, enclosing an areaone or more liberties (called an eye) can makegroup harderkill, sinceopponent must cover allits external liberties before coveringfinal, internal liberty.
From this, itpossiblecreate groups that cannot be killed at all. Ifgroup encloses two or more separate areas (two or more eyes),opponent cannot simultaneously fill boththem withsingle play,thus can never play onlast liberty ofgroup. Suchgroup, orgroup that cannot be prevented from forming such an enclosure,called alive.
Groups whichnot definitely alive nor definitely deadsometimes called unsettled groups. Much oftactical fightingGo focuses on making one's own groups live, by ensuringcan make two eyes,on makingopponent's groups die, by denying them two eyes.
Reading
Determining aheadtime whethergroupcurrently alive, dead, or unsettled, requiresabilityextrapolate fromcurrent positionimagine possible plays by both sides,best responsesthose plays,best responsesthose responses,so on. Thiscalled reading ahead, or just reading,it isskill that growsexperience. Many players study bookslifedeath problemsincrease their skill at reading moremore complicated positions.
HighLow
ThicknessLightness
A position that cannot be attacked, that is, one which can easily get two eyesfor which therenot many moves that havebe answered,called 'thick'. Thick positionsimportant asradiate influence acrossboard. An error thatoften made by weaker players ismake territoryfronttheir thick position; thisan inefficient wayscoring points. The correct wayuse thickness ishavehelp inattack ofweak group ofopponent, or insaving ofweak groupyour own.
A light groupalso one thathardattack, but fordifferent reason. Ifgroup haslarge numberoptions, often includingsacrificepartit, itcalled light. Because itusually impossibletake away all or almost all options, attacking suchgroupvery hard foropponent, attacking suchgroup will bring little advantage. A weak group which cannot be sacrificed at willcalled heavy.
AttackDefense
A large part ofmiddle game ofgameGousually spent by one player attackingother player's weak group(s). Whatimportantrememberthatmost casesgoalan attacknotkillattacked group, butgain territory or influence. The attackmore or less usedrestrictopponent's optionsmakeimpossiblehimmake territory or influence himself.
TerritoryInfluence
See Go concepts
Ko Fighting
Whenko occurs,player whose stone was capturedstartko cannot immediately recapture; he must play elsewhereprogressgame so thatrepeating position does not occur. However, this allowsplayer who startedkodenyopponentchancerecapturestone (usually by connecting that stone backan own group, or by capturingfurther stonefree more liberties). Thus,player findingmove elsewhere would preferplay such thatoriginator ofko findsmore valuablerespondthis new play, thanignore itcompleteko. Suchmove, threateninggain advantage if itignoredcompleteko,termedko threat.
Onceko threatmade,player originatingko haschoose between responding tothreat, or completingko. If she responds tothreat,player who madethreat can then returnrecapturestone that startedko. The situation then becomes reversed;player whose stone was recaptured wantsfindko threat that allows herrecapture again. Suchsequencemoves -- startingko, followed byko threat, followed by recapturingko, followed by another ko threatso on --termedko fight.
Eventually one player will winko by ignoringlatest ko threatcompleteko. The player who madelast threat therefore getsfollow up on it,effect getting two movesanother part ofboard whileopponent completesko. Itthus worthwhile choosing ko threats that will givedefinite advantage if ignored.
Before decidingstartko, itworthwhile evaluating what threatsavailableboth players, so that one can decide which sidelikelywinko fight. Many ofplaying skills come togetherko fighting (evaluatingvaluemoves; reading aheadfind likely moves ofopponentbest responses; choosingbest ordermoves),it istopicmuch discussion among players. This also causes many beginnersbe fearfulfightingko, since theynot confidenttheir abilityevaluate threats.
SenteGote
'Sente''gote'terms thatmuch usedGo theory. The player who has sente isone whose move itoncelocal continuation has been played out. The player who does not have sente has gote. A sequencesaidhave been playedsente ifplayer who startedhas sente afterward. Having or losing senteimportant, as taking gote unnecessarilyequivalentpassing.
Opening (fuseki)
The first movesusually played on or near4-4 star points incorners, becausethose places iteasiestmake territory. After that, standard sequences (joseki)useddivide corners,extensions alongsidemade. Usually,center areakept emptylongest. Playsusually onthird or fourth line -second makes too little territory, whilefifthtoo easily undermined byplay onthird. A play onfourth linedirected more towards influence tocenter,play onthird line more towards making territory alongside.
Endgame (yose)
Inendgame, ifgameclose, moves thatsmallstill worth some points, some more than others. One must chose whichthese movesmore urgentplay based not only onpointsmay gain, but on whether that movesente. Yose refers tospecific kindendgame play, which yieldsreductionyour opponent. Generally, inendgame, allterrritorystaked out - thereno morebe gained. However, therestill pointsbe made, as well as possible waysreducing small amountsyour opponents territory. A simple example would bemove thatdame (neutral pointyou) but when its filled in, its sente, requiring whitefillstonehis territoryanswer. We say this'a one point reduction,sente.'
To continue, see Go concepts Also Go theory
