(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2] RU[Japanese]SZ[19]KM[0.00] PW[Counting]PB[Counting]DT[2003-03-132003-03-13]PC[The Kiseido Go Server (KGS) at http://kgs.kiseido.com/The Kiseido Go Server (KGS) at http://kgs.kiseido.com/]C[Copyright Steve Fawthrop, 2003, 2013 =============================== ] (;C[This lesson is going to try to put together a lot of the things we discussed in the first four lessons. Specifically, we are going to look at how to play in situations where either player has a clear lead, say 10 points or more. I will assume that you are familiar with the topics covered in the previous lessons but if that is not the case I would suggest that you review them and then review this lesson later. The first question that comes to mind is: What does it mean if we say that B is clearly leading? The problem is that this statement by itself does not help a whole lot. We must look at the three types of territory: definite, probable and possible, before we can get a clear answer. This was covered in lesson one and so we will not review it here. In all positions in this lesson we will not actually count. I will give situations and tell you want to do, but you are going to have to do the work yourself later. Thinking about this in more detail we recall that to determine whether you are ahead or behind you must look at the three types of territory: definite, probable and possible, before we can get a clear answer. It is no good saying you are ahead without qualifying it. Are you ahead in definite territory? Or is the definite territory equal but you have way more potential? Both of these would give you way ahead according to our methods, but they are very different So,.we will look at different situations becase they require different strategies. But remember, the root of all our discussion is the act of counting. You cannot decide if you are ahead without counting and you cannot say if you are safely ahead without know the different types of areas]) (;C[Let's start off by looking at a position in which B is clearly leading in definite territory. Moreover, we will assume that B has so much definite territory that there is almost no way for W to catch up. Let us try to determine a strategy. In the lesson several people suggested playing defensively This not a good idea? The problem is that the playing defensively tends to lead to being OVERLY defensive. So what should you do? The best approach is to play securely , but not overly defensive. But first make sure that, if W gets the MAXIMUM your count allows (for definite, possible and probably territory) that maximum will not add up to more than your definite Note that this does NOT mean play defensive. It means to make sure you get what you deserve, but do NOT try to get any more. If you try for more you may over stretch and make a mistake. Let's look at a position. ] ;AW[dc][gc][ce][ge][gg][em][lm][mm][cn][en][gn][nn][on][bo][do][no][po][bp][dp][fp][hp][jp][lp][np][pp][bq][cq][oq][pr]AB[ic][oc][qd][ie][oe][cg][pi][cl][el][kl][ml][bm][dm][nm][om][bn][dn][jn][ln][mn][pn][qn][qo][qp][pq][qq]LB[eg:B][ig:A]C[How do we evaluate this position? Cleary W has played very conservatively here. B has a lot of solid territory, far more than W. The question is, does B have enough with his huge territory and moyo on the right ot win this game? Counting definite territory only we see that B has more of it than W has in definite and probable combined. This is VERY favorable. B cannot lose his definite territory unless he makes an awful blunder and even if W gets ALL his probablty territory he will not have enough. Remember, that the first thing to do, always, is count the score. Here this is left as an exercise, but you should find that B is way ahead in definite territory. So, can W match that by counting his probable and possible territory? It seems not, unless B is VERY careless. Where can W gain more territory? There does not seem much potential for W in the middle but that is the only place. So , what is our strategy as Black? B has enough definite territory to win easily unless W can secure a LOT more. Since W can only do that in the middle, B's strategy is NOT to try to get any more territory, but to stop W from getting any more. In doing so, B WILL get some more in the upper middle because he has more potential than W, but the point is , he does not need it. So do not get hung up on grabbing any more. Just play carefully and make sure W does not get a large live group with territory in the middle unless B gets some compensation. Also, it is important to not let W invade the left as that may start a fight in which the balance shifts. It is important to avoid fights when solidly ahead. Having said this, where should B play? The most popular choice among those in the lesson was to play A. We will look at this and then give reasons why a B play at B is better. ]PL[W] (;B[ig]CR[ig]C[This move looks huge, and it is. It will almost certainly lead to a win. For most players of mid-kyu strength or above W would not have an chance after this move. But for weaker players this may be a little risky. So what is wrong with it? ] ;W[bk]CR[bk]LB[ig:1]C[I B plays as in the previous diagram it is just conceivable that B might get into trouble on the left. Suppose W tries something like this. This is definitely an overplay, but it is also a move which might confuse a weaker play. It is distinctly possible that B might get into serious trouble here and, if so, W can then later try to reduce the top right. That is not to say that this should, or would, happen, but if it does then the balance of definite territory is shifted drastically. So, instead of playing B1, is there another approach which B can make to eliminate this risk? This is shown in the next variation. ]) (;B[eg]CR[eg]C[If B plays here what can W do? W must now try to reduce the B moyo, but we already said B has enough definite territory so he does not need his moyo. The other option we considered has a potential for far more complications than this move. So the lesson from this position is .... COUNT THE TERRITORY BEFORE MAKING A MOVE AND MAKE SURE THAT THE MOVE YOU PLAY WILL KEEP YOUR SOLID LEAD WHEN YOU HAVE IT AND DO NOT PERMIT COMPLICATIONS WHEN YOU HAVE A FIRM LEAD IN SOID TERRITORY One possible follow up is shown.] ;W[ih]CR[ih] ;B[jg]CR[jg] ;W[jh]CR[jh] ;B[kh]CR[kh] ;W[ki]CR[ki] ;B[lh]CR[lh] ;W[li]CR[li] ;B[mi]CR[mi] ;W[fi]CR[fi]C[This is typical of the sort of thing W can do. But now B has even more definite territory than before. If we recount this is even better for B: W will get a little in the middle but B has got a lot more in upper right The only option to this sort of sequence for W is to invade the top right deeply, but here this does not look like l winning strategy. ])) (;C[Now we will consider the situation where Black is ahead by virtue of probable territory, not definite territory. In this case let us assume that definite territory is about equal (or maybe W ahead) but B has a big lead in probable territory. Let us try to determine a strategy. Ideas suggested in the lessons were: secure the probable territory; make some more definite territory; expand the moyo; attack W if he has a weak group and use the attack to build influence. But all of these are a little vague. We need something more definite to go on Let us assume that the definite territory is about equal and let's look at the probably territory. In the position under consideration we assume B has a lead in probable territory so it is natural to ask ourselves if it would be enough to secure all of this? The answer is "probably yes", but it is not likely that B can secure it all. W will surely fight back because if B gets all his probable and W gets all his then B will win. So that would make little sense for W and he will NOT try to securte all his probaly territroy: he will INVADE. So, if we know that W is going to invade with striaghtforward play by B what should we do? Our goal should be to find a move which will secure some of your probably territory and minimize the chance of an invasion. So you look over the board and try to find a place whis will do this. Let's look at a position ] ;AW[cb][db][dc][ic][lc][ed][fd][gd][ee][re][ff][gf][qf][ch][dh][ph][qi][bj][dj][dl][pm][dn][pn][qn][po][dp][cq][cr]AB[bb][bc][cc][fc][oc][qd][rd][ce][fe][ge][he][oe][df][ef][fg][hg][og][bh][eh][nl][fn][on][qo][hp][kp][qp][fq][nq][pq][dr]LB[fk:D][gk:C][fl:A][gl:B]C[If you count this position you will find that there is no a big difference in definite territory but B has a large lead in probably territory. To win B must convert more of this probable territory than W does. Where can W invade with any hope of success? Let's first dismiss some possibilties first. Extending to one of the point A-D is not an invasion and will not be enough for W. To win W must reduce B considerably as just erasing from the outside will let B secure his probably territroy L6 was suggested during the live lesson and is worth considering. K3 was also suggested, but it probably a little deep and would involved considerable risk, . I would say that the only thing for W is to start a big fight and hope it overflows B's definite territory, so where can W do this? Let up look as a few variations. ]PL[W] (;W[gl]CR[gl]C[As we said, this is not an invasion and will not lead to enough. ] ;B[hm]CR[hm] ;W[hl]CR[hl] ;B[il]CR[il] ;W[ik]CR[ik] ;B[jk]CR[jk] ;W[gm]CR[gm] ;B[hn]CR[hn]C[B will secure a lot of his probable territory. This is what B wants so this is no good for W, who gains little. ]) (;W[kn]CR[kn]C[This is worth considering but it is too far from support inside B's influence. W cannot hope to get away with too much. ] ;B[kl]CR[kl] ;W[mn]CR[mn] ;B[mp]CR[mp] ;W[oo]CR[oo] ;B[no]CR[no] ;W[om]CR[om] ;B[nn]CR[nn] ;W[nm]CR[nm] ;B[mm]CR[mm]C[W is more likely to get into trouble by initially playing too far from support. ]) (;W[jl]CR[jl] ;B[jn]CR[jn]LB[mn:A]C[And if W tries a shallow reduction like this then B can just grab some of his probably territory and keep ahead. So what is W's only chance? I would play a A hoping to use the threat to connect to the right in order to run to the left. ]) (;B[ok]CR[ok] ;W[qk]CR[qk] ;B[no]CR[no]C[This is what I propose. Solidify the connection before W has a chance and build a little more probable territory in the process. So how should be summarize the lesson from this position? B and W are about equal in definite territory but B has way more probable territory than W. As long as that stays that way he will win: there is no need to rush to grab that territory. W will have to try to reduce it to win so a move which adds to the potential and at the same time stops W from invading is a good move. The moves in this diagram seal the weakness on the right. How have these moves changed the position? They have not shifted the blanace of definte territory and they have not changed the probable much either, but they HAVE made it hard for W to invade and reduce the probable territory. So they have moved B a step closer to victory. This is NOT the only strategy, but is it one i recommend and it will usually work ])) (;C[This time definite and probable territories are about equal but B is way ahead in possible territory Let us try to determine a strategy. We assume that the definite is equal and the probably is equal. If each player gets what he deserves from this they are still equal. The fact that B is ahead in possible territory is not a big deal: it is merely possible, and that does NOTalways translate to real territory. B could play a mutual reduction strategy and exchage his probable for W's or he could play so that both will claim their probably. Is there a difference here? Let's think about it. Possible territory merely means that it is closer to one player than the other. That does NOT mean it will turn into territory So B must decide which is these two strategy - mutual reduction or mutual claiming - will help him the most. Which will help turn some of that possible territory in real territory If B just blindly takes one option without thinking what will happen he may find himself losing out in the possible territory So the idea is to try to keep the balance of probable territory while affecting the balance of possible. It is not important how the balance of probable is maintained - only that it IS. But you must NOT forget to consider this balance after every move. Let's look at a position. ] ;AW[dc][jc][lc][mc][ce][je][hf][eg][fg][dj][dm][go][ho][cp][gp][ip][eq]AB[nc][oc][md][qd][lf][ig][fh][gh][oj][qj][po][hp][gq][hq][iq][jq][mq][pq]C[How do you evaluate this? Definte territroy about equal? How about probable? There actually is not a lot of probably territory for either player here so, how can we maintain the balance or probable? There is a lot of possible territory in the middle and B has a better claim to it. Is this the time to prevent an invasion? Earlier we said the strategy was to stop invasions, but this is different If B were to worry about an invasion here then W would get the advantage in claiming the possible territroy IT IS IMPORTANT HERE TO ALTER THE BALANCE OF THE POSSIBLE TERRITORY AS QUICKLY AS POSSIBLE. B CANNOT PLAY A SLOW MOVE: HE MUST PLAY IN THE CENTER Our strategy is .... WHEN DEFINITE AND PROBABLY TERRITROY ARE EQUAL YOU SHOULD PLAY TO MAINTAIN THE BALANCE OF PROBABLE TERRITROY WHILE TRYING TO SECURE THE POSSIBLE TERRITRY , WHICH IS WHER Y OU HAVE THE ADVANTAGE Just remember - it is the BALANCE of probable territory you must maintain, you do NOT need to grab it all for yourself. And remember, just becasue there is no probable territory now , does not mean that W cannot convert some of his possible into probable territroy and upset the balance of probably territory.. ]) (;C[Now let's look at when B is behind in definite territory. Because we have looked in more detail when B is ahead we only need no look at a few position without a preliminary discussion.] ;AW[dc][jc][mc][rc][rd][de][qe][if][qh][cj][qj][rj][rk][dn][dp][eq][fq]AB[rb][oc][qc][qd][oe][oh][pj][pk][qk][rl][gm][pn][fp][jp][gq][nq][qq][gr]C[What is B's stategy here? He is definitely behind in definite territory. Can B win without disrupting the balance of definite territory? Probably not. So it is B's first priority to disrupt this balance. How does B upset this balance? There are two ways: add to his own or reduce the opponents. Dependiong on the position, both are effective. If B invades in this position it will probably work - W will lose some territory. But W will get strong on the outside and this will affect the balance of probably and possible territroy also. You will need to imagine the outcome and then try to assess the score. If B just tries to reduce then secure this will minimize the W definite territory It will then probably increase the B definite territory which will . Also it will like shift the blanace of the possible and probably in B's favor becasue B will be playing in the middle firest Just trying to secure territory will increase B's definite territory but will not limit W's and so W has the chance of more definite territory. This will not affect the balance enough. Let us look at some possible sequences. ] ;B[el]CR[el]C[How can W resist? This? ] (;W[cl]CR[cl] ;B[ei]CR[ei] ;W[dh]CR[dh] ;B[ih]CR[ih]C[This was my idea for this postion. There has been a drastic shift in probable territory while limiting W's definite territory. This show that B does not need to panic and invade deeply in a position just becasue he looks to be behind. ]) (;W[dl]CR[dl] ;B[ek]CR[ek] ;W[ij]CR[ij]C[W could try to resist like this. ] ;B[ck]CR[ck] ;W[dk]CR[dk] ;B[dj]CR[dj] ;W[cl]CR[cl] ;B[ci]CR[ci] ;W[bk]CR[bk] ;B[ei]CR[ei]C[But then B effects a huge shift on definte territory which is not good for W. The potential is still about the same so B has gained. ])) (;C[now let's look as a position where definite territories are about equal but B is behind in probable territory ] ;AW[dc][jc][de][ci][qi][ql][om][dn][ln][jo][cq]AB[nc][qc][qg][qn][po][fp][ip][lp][eq][jq][pq]TR[dc][jc][de][ci][qi][ql][dn][cq]C[How do we assess this? B is behind in definite and probable. B only has the bottom and top right as definite. These stones define a line which had mostly definite behind it So when we combine definite plus probably W is ahead Can we change this balanace? There is no right answer here but you should think about possible strategy. B could invade the left, and he would live, but is this best? It could be for some players depending on style, but invading will allow W to increase the outside influence and the balance of possible territory. If B is too agressive and invades he may get away with it but he may also give W a lot of thickness ot shift the balance of possible and probable. This may be risky. I prefer to leave the balance of definite territory for later and change the probable now. Can B attack the right side stones? ] ;B[nn]CR[nn] ;W[nm]CR[nm] ;B[mm]CR[mm] ;W[mn]CR[mn] ;B[ml]CR[ml] ;W[kl]CR[kl] ;B[mj]CR[mj]C[This is playable for . Can the 3 B stones be killed? Probably not. But now W has two weak groups. W will not die, of course but as he is livinig B will be able to shift the blance of possible and probably territories. So to summarize: If the position is vague, as here, look for a possibility to start a fight. But not just ANY fight: one which will allow you to shift the balance of one of the types of territory. Don't just fight for the sake of it without any gain. If you are not aware of the balance of territroy as you fight you might as well not fight. First look for a way to shift the balanace of definite. If there is no good way, look to shift the probable and only as a last resort try to shift the possible BUT, with every move be aware of these three balances and how they afferct you possible outcome of the game ]))