Alguien wrote:As middlegame goes on, most of my games reach a situation where I'd be about 25 points ahead if all my frameworks became territory. My opponent invariably starts attacking very aggressively and I win or lose depending on how well my frameworks hold on.
What I'd like to know is: What should I study to play fuseki and beggining of middlegame in a way that helps me defend against cornered opponents?
Also, is that the correct question? Or I should rather study how not to reach that situation at all and start securing territory much sooner.
OK... Personally I think the questions are all incorrect. Simply put, you can not play Go expecting the game to be over in the fuseki or beginning of the middlegame. There is a reason that it is called the "middle" game, i.e. it is not over yet. Even then, correct questions depend on the situation:
Version 1: Your self assessment is correct. Your frameworks "should" turn into territory. So you should study how to profitably attack the unreasonable invasions of your opponents. This requires two things on your side. (Note that if this is actually the case on average then you are much better at fuseki than you are at fighting. Your lack of fighting skill is dragging you down.
But this is not likely to be the case, since being good at fuseki normally requires that you are able to comprehend the potential of future close-in fighting. In other words your topic may be mis-named.

)
First, choosing the right direction of play, i.e. your opponent does not die but you solidify more territory by attacking from the left rather than the right and chasing them into the center rather than forcing them to make two eyes on the side. This is about overall judgment of the board as a whole and understanding the potential in your positions as well as those of your opponents. If you chase a one-eyed group into the center, how do you do it in a way that gives you an easy invasion of the oppo's largest territory over there on the left side? The first step is looking beyond your supposedly unassailable frameworks to your oppo's areas. Which are too strong to invade? OK, there is no good direction of play toward them. Which are still subject to invasion/reduction. OK, there may be opportunities in that direction. Personally I do not think there is a lot of good, well-organized material for studying this type of issue. YOU have to step up and think about it in your games.
Second, playing efficient attacks, i.e. you manage to actually kill them if they give you the opportunity, or you keep the pressure up as long as possible (taking territory/making thickness along the way), without letting them slip away in a profitable fashion. This is about the vital points of shape and how to attack them. There are lots of tsume-go and tesuji materials to study, but it requires considerable effort from your side to apply them "in the wild" as it were. The best lessons come from trying and failing, then trying again.
Version 2: Your self assessment is not correct and your frameworks are subject to invasion/attack. (I find this much more likely. My own experience of 30 years of teaching games with various pros in Japan is that we amateurs simply do not see anywhere near the potential of the positions we create on the Go board.) This requires two things:
First, choose the right direction of play! Whoa, what the heck!!! Yes, really. Sorry to say but whether we are right or wrong in our dream-like imagining of the future, once our opponent contemptuously slaps down a stone in our face, we have to react! (Sheeessssh, yeah I know, no one explained it quite that way when you first got interested in Go, but nevertheless...) The key to large-scale fighting is always about the potential in the other areas of the board, aka direction of play. If I attack from the left and he lives, how much can I make? If I attack from the top and he lives, how much can I make? These are the real fundamentals of attack and defense.
Second, (by now you can guess, right?) play efficient attacks! Even if you are behind, the road to catching up is playing more efficiently than your opponent down the stretch. After all if you are rated the same and your oppo gained an advantage in the opening, you may well be better at middle-game fighting. Think positive and keep attacking (see above).
Version 3: Your self assessment is completely wrong, your supposed frameworks are nonsense and your oppo's territory is unassailable. I hate to say it but this is a real possibility for a DGS 5-kyu (sigh!

) Nevertheless, this situation is relatively easy, go back to basics and study the opening.

Although to be honest if your oppo is equally rated, there ought to be countervailing weaknesses in their play to make up for a superior opening, so you can contemplate just letting all the study slide and out-fighting them in the end. It is probably what I would decide to do while fetching another beer from the fridge. How did we put it when I was young? "F*** em if they can't take a joke!"
