1. Reading

No tesuji per se, just a reminder that you can only find tesuji and ensure they work by doing exhaustive reading.

2. Capture the cutting stones

a. Knight's move - for making a net, a niken tobi/keima jump is often harder to cut through than a ikken tobi/ikken tobi jump.
b. Loose ladder - when the surrounding stones deny the target stones any double-atari possibilities, the ladder can work even though the target has liberties.
c. Slap - with the right surrounding stones, the fourth point in a bamboo joint is useful for setting up ladders, loose ladders, squeezes, etc.
d. Clamp - a net can work even when there is an enemy stone wedged between the net.
e. Nose - playing the nose of the target restricts its mobility and can make it hard to avoid a net or loose ladder.
f. Cross-cut - here, a cross-cut is like a sacrifice double-nose hit, blocking new liberties in two directions; this sets up a shortage of liberties if the target tries to capture the cutting stones, but makes it impossible for him to win the capturing race if he doesn't.


3. Amputate the cutting stones
a. Snapback
b. Throw-in - as a capturing technique this is most useful when it gives the group the "empty triangle on the edge" shape.
c. Squeeze - a clever squeeze will have more than one stone in atari simultaneously; the one that isn't capture can pull out and begin the squeeze.
d. Ladder-building - i.e., a move that will make two ladders miai.
e. Placement - here, a move behind enemy lines will cut off a target stone that will have fewer liberties than the placement stones. You can extend while threaten to connect, and start off a move ahead in the capturing race.

4. Ko
This chapter is really about types of ko and using tesuji to make a ko more favorable, e.g. by making throw-ins.

5. When liberties count
a. Approach moves - Sacrifice a stone in sente to reduce liberties and force the opponent to completely capture the sacrifice stone before he can put your main group in atari.
b. Descent - if the enemy will have shortage of liberty problems on both sides, descending to the edge wins an extra liberty.
c. Throw-in - Throw-ins help you retain sente in capturing races; look to create the false eye after the throw-in has been made.
d. Two-stone edge squeeze - (aka ghost head, tombstone, etc.) As clever as this looks, it's mainly a device to capture the two stones sticking up, not the awkward shape on the edge. The corner version doesn't necessarily create a false eye - you need to be prepared to lock him in the corner and capture that way.
e. Fast squeeze - The target stones have one of your stones in atari. You put them in atari a keima away from the atari'd stone. It looks like you have bad shape if he descends, but you can pull your own stone out of atari to capture. If he captures, you squeeze.
f. Belly - one of the implicit possibilities of the belly is to pull the belly stone out on the first line.
g. Gaining liberties - with a placement. Similar to the cross-cut; if he firmly cuts the placement off, the target stones are isolated and captured, but if he firmly connects his own stones, you can gain the liberties you want.
h. Eye - eyes add approach liberties.
i. Diagonal - approaching the edge diagonally gets you an approach liberty (the tiger's mouth).
j. Big eye - extra liberties. They don't mention the extra approach liberties, but worth remembering.
k. Safety play - this is just the descent tesuji, but with groups that are spread parallel to the first line instead of perpendicular. Again, the enemy has an extra approach move on one side, but makes an empty triangle if he approaches on the other side first.
l. Two Hane - when you have stones on the second line and two hane on the first, and both hanes have two liberties, then either the enemy has to capture one of the hane, or you can capture the stones he plays on the first line and gain a new liberty simultaneously (by connecting to a hane).
m. Ko in capturing race - If one of the liberties in a capturing race is a ko, it's worthless to take the ko while you can still use external liberties as "ko threats". Best to take the ko when you can win it by capturing, making the external liberties worthless.

6. Linking groups together
a. Knight's move - this is two keima at a pi/2 angle, from the third/fourth to the second line. It holds despite the ogeima between the original two stones being seriously compromised; however, you need to extend once on the second line, so you need to be able to defend both cutting points when the enemy pushes between a stone on the second and on the fourth line.
b. Clamp - a clamp which is also a kosumi from one side threatens to cut (making a hanging connection), and so should allow you to connect underneath.
c. Shortage of liberties - here, the technique is to connect underneath, starting with a hane from the stronger side. If the enemy blocks, preventing you from connecting above leaves him him in atari, but capturing the hane for an extra liberty just leads to death.
d. Sacrifice - a sacrifice can make two cuts that had seemed miai run into shortage of liberty problems.
e. Diagonal - a kosumi from endangered stones onto the first line can link even if the relation of the kosumi to the outside friendly stones is awkward. The diagonal tesuji is also a good capturing race tesuji, so if the enemy obstinately cuts, you have already played the vital move.

7. Cutting groups apart
a. Cuttable and Uncuttable shapes - the one-point jump is cuttable (wedge-atari-extend, two cutting points are miai), but cutting hugely strengthens black unless white has stones directly supporting the two cutting points. The two-point jump is cuttable (attach inside, hane, counter-hane, atari, extend: laddering the cutting stone and cutting at the other point are miai), but again, other nearby stones change that. Knight's move cuts depend on ladders; if you add a stone to make the dogs neck, at least one of the knight's moves will be uncuttable.
b. Cutting the knight's move - consecutive knight's moves from the second to the third line can be cut by attaching to the central stone on the second line. If black tries to preserve both jumps, the third move puts the central stone in atari. The basic strategy (attach-block, attach-block, atari) can be used in various knight's move + ? combinations.

8. Into enemy territory
a. Wedge - i.e., the atekomi wedge. Hard to characterize.
b. Belly - here, the implicit threat of the belly isn't connecting under but cutting (with the aid of a friendly stone nearby, to make a hanging connection). Same as before - the belly tesuji aims at either completely enveloping the sides, or hitting both noses, of the two-stone group.
c. Placement - here the theme is moves that can function either to pull stones out of atari, or as a placement - white can only block one.

9. Escape
a. Wedge-and-Cut - a wedge that doesn't work after you connect can be left in atari to cause shortage of liberties.
b. One-point jump - sacrifice the jumping stone to capture something on the other side of the two stones it's jumping off of.

10. Sacrifice to gain tempo
a. Cutting the knight's move - same as cutting into the double knight's move or knight's move combo, but here the point isn't to cut, per se, but to sacrifice the inside attachment to get the outside attachment in sente. (The sacrifice is only necessary when white has a sente response to a direct outside attachment.)
b. Cutting - threatening one cut (with the requisite sacrifice of one stone) accomplishes another cut in sente. If black just cuts without the sacrifice, white gets sente to pull out the cut stones; if black seals in the stones without cutting, white connects.

11. Tesuji for attack
a. Eye-stealing - this works best when the target stones only have three liberties, one of them being the false eye: attempting to cut off the eye-stealing stone leads to a squeeze.
b. Placement - here the theme is stealing eyespace. First peep at a cut; then draw back a space, threatening both a hanging connection and a solid connection.
c. Drawing back - make a knight's move rather than a hane. After the hane, you have to let him crawl on the second line multiple times. After the knight's move, your stones have more liberties and you can cut him off faster. You don't defend the knight's move directly; instead, play the second knight's approach to your first knight's move. A solid, two-stone block and cutting are now miai.
d. Double hane - if you just want to seal a group in and don't mind giving white a ponnuki on the outside, double hane when the enemy stones on the third line only have two liberties.
e. Eye-stealing-clamp - specifically, a clamp that threatens to pull a single stone out of atari. You've destroyed an eye, and it will be difficult for white to get out with the clamped stone, which only has two liberties.

12. How to connect
a. Solid - not developmental, but allows fewer peeps than a hanging connection.
b. Diagonal (hanging) - allows a peep, but prepares for good development in terms of the knight's jumps from the kosumi stones; prepares for moves which make good eyeshape. [Also, can prepare to block on the first line in sente: prepares to hane under on the second line in sente.] The knight's move is even more development, although it is thinner; it is best used when two thick walls meet at right angles.
c. Eye-protecting - prevents the eye-stealing tesuji, prepares an eye.
d. Indirect - moves distant from the cut will protect against the cut if, for example, they create a shortage of liberties for the cutting stones after an atari or a throw-in.

13. Making shape - "To make shape is to take a weak or defective position - perhaps only the sketchy outline of a position - and transform it into a strong one."
a. Squeeze - by sacrificing a cutting stone, black can get nice straight lines while only giving his opponent a dumpling in return.
b. Counter-hane - Black is trapped in enemy territory. A one-space jump headbutts an enemy stone. White hanes on top; black counter-hanes. Now, if white gives black a three-stone pole to put the second-line stone in atari, black can catch the original white hane in a ladder (or make some sort of shape, if the ladder doesn't work). If white cuts the original 1-space jump instead of giving black the three-stone pole, black makes a ponnuki on the edge.
c. Cross-cut - After a one point cap, black attaches to the capped stone; when white hanes under, black cross-cuts; if white captures the cross-cutting stone, black gets two ataris and can make the double hanging connection (or something lighter). If white takes a ponnuki to prevent the second atari, black forces him to connect the ponnuki and then sets about making the carpenter's square. The basic pattern is that the attacker needs to either make a clunky ponnuki and permit two ataris, or permit an atari on the ponnuki that he will later need to capture while the defender continues to improve his shape.
d. Driving - atari followed by nose tesuji; by the time the enemy stones have escaped, the defender has a solid line of stones.
e. Attachment - here, the theme is that white has cross-cut from a strong position. Black attaches to a nearby stone; if white defends that stone, black ataris the original cross-cuttin stone and the driving tesuji is on; otherwise, he's a move ahead in the new fight. Works with different tesuji combinations.
f. Using dead stones (zombie) - the emphasis here is on cutting stones with two liberties on the third line. Descending to the second line on the outside, though sente, is a waste. Try to find some nearby move like an attachment that requires a local response, but also protects the outside stone enough to permit the inside descent [the zombie cathedral tesuji].
g. Hitting under/Hitting over - hitting under (on the second line) is basically a transposition of the cross-cut tesuji. Hitting over is familiar from many joseki, hard to say what makes it a tesuji.

14. Ignore the atari
a. Don't atari [threaten the atari] - atari is usually clumsy, but threatening the atari allows you to develop.
b. Counter-atari - what is sounds like. Flavors: white won't capture the stones anyway, so don't give yourself bad shape; squeeze white after the capture, and then loosely surround him.

15. Double threat tesuji - what it sounds like.

Otake

Three groups of principles. The first group is about fuseki as it is normally understood; the second group are shape taboos; the third group are strategy guidelines.

Fuseki
1. 3-4 enclosures --> side extensions
[One direction is bigger because it allows a boxy moyo. Dual extensions are also bigger than extensions where only one corner can develop. A shorter (i.e. <5 space) extension can still be big.]

2. Be flexible with star points
3. Choose a pincer
[Pincers prevent a secure two-space extensions. There are six pincer choices. A loose pincer can double as a side extension. Likewise, a sequence in one corner can be made to end in an extension than is a pincer in another corner.]

4. Anticipate invasions
[When you choose an extension, read out the invasion and play accordingly. At 3 spaces, jumping up to the 4* line makes it easier to connect. But any kind of extension can be secure if one stone has a sente jump and the other has room for a secure two-space extension; they are separate but stable and can attack the invasion.]

5. 3* vs. 4*
[[The key point here isn't that the 3* line is territorial while the 4* line aims at influence; it's that a 4* line requires a further extension down to the 3* line both to make potential territory and to have secure eyespace, while a 3* line stone doesn't. So another way of putting this is, the 3* line is sente and the 4* line is gote (you're committing yourself to a final, finishing move on the 3* line after your opponent extends). Thinking ahead, this means that if the potential follow-up extension to the second extension is big, or is dual-purpose, the 4* line is good (4* line -> big finishing move on the 3* line -> aims at a final big extension), and if the potential follow-up is small (sometimes this means there's no room for a fourth extension) or approaches thickness, the 3* line is good.]]

6. 5-4 --> outside influence
[[This is really just a few 5-4 and 3-5 josekis. If anyone got more than this out of #5, let me know.]]

7. Build boxy moyos
[Not only are squared shapes efficient and easier to defend, but they're 3D; a further extension off one side makes it very easy to expand the whole moyo.]
[[Two further points. One, every time you add a boxy extension to your moyo, you are practically guaranteeing that whatever the opponent does to reduce, you will get all the potential territory that was in the original moyo. Two - this is not explicit in Otake, but having room for a further extension means that if your flat moyo is invaded, you can extend down the side and settle there. Once you don't have room for an additional extension, adding a second story means invading is no longer practical, since the invasion comes under such a severe attack.]]

Shape
8. Family feuds: taboo
[[The principle of the shape section is that every stone needs to be 100% efficient. Sometimes this means making your local string of stones efficient (this is what I usually think of as "shape"), but global efficiency is also important. A stone that starts a "family feud" is globally inefficent in the same way that capturing in a ladder or fighting a ko is inefficient: Whatever strength you gain on one side loses its efficiency when the enemy leans on one group, gaining some strength, and then returns to attack the original group. When you play both sides of the "family feud," your position just gets ridiculous. Ways to avoid family feuds: (i) Completely sacrifice one side, if profitable. (ii) Play a shy-looking move that threatens to move in two different directions. Now attacking one of the other groups doesn't put any pressure on the first group (which now aims in the other direction), so the global efficiency of your position is fine. (iii) Where there is only one group you're worried about damaging, move in the opposite direction - or play an inducing move that strengthens the second group and then "forces" you to move the first group in the opposite direction.]]

9. Hane at the head: taboo
[[The most efficient way for a group to develop is by extending or jumping from it's head/nose. The hane at the head, then, removes the most efficient way for a group to develop. It's best to stay ahead (or hane, if possible) even if that means giving the opponent a wall that can subsequently be used in an attack.]]

10. Empty triangle: taboo
[[Here the emphasis is on learning how to move out with 1-point jumps from two stones, rather than empty triangles.]]

11. ??? (Dont' push from behind)
[[This is tightly connected to the taboo on getting hane'd at the head. If you can extend in two different directions, extend in the one that puts you ahead. If you can jump ahead, jump ahead. If you can push from behind once and then jump ahead, do that. If there's no chance of getting ahead, don't push at all: play one of the shy looking moves that looks to two different directions. Now the opponent has no obvious efficient move.

12. Atari: taboo
[[Atari isn't taboo per se, of course, but the key point here is that if you ultimately need to defend cutting points or need to extend in a certain direction, do that first. Even if the extension doesn't threaten a ladder, (like the shy moves) the calm extension/connection leaves the opponent without an obviously strong response: strengthening himself locally is gote. Sometimes the unnecessary atari is strengthening the opponent in coming fighting, sometimes its strengthening his territory and turning a position with lots of bad aji into secure territory.]]

13. Permitting ponnuki: taboo
[[The key point seems to be that the ponnuki is both very secure (easy eyespace) and very developmental (lots of good direction to make jumps from all those kosumi.) Otake even praises the ponnuki-in-ko, which I've always found unhelpful. He specifically criticizes not taking the side the opponent offers in a sacrifice-cut-and-ladder-capture on the second line: it is not the corner that is big or the side that is big, but the sturdy, fast ponnuki that is big, compared to a heavy, slow full triangle. Loons told me this just the other day, but I was too stupid to believe him.]]

Strategy
14. ??? (Steal the base)
[[In practice, stealing the base always means blocking off access to the corner. The corner is always bigger, not just because there are points there, but because there's so much stability and security at stake. And stabilizing in the corner is forever. Once you let a group have "a little bit" of access to the corner, whatever attacking moves the you try on the outside, it can get even more stable by burrowing further into the corner. When you block of the corner and force a group into the center, whatever attacking moves you had in the center will still apply pressure, but if you play at attacking move in the center while the corner is still open, the group can stabilize completely in sente and the attack is over. Blocking off the corner is also a classic example of a profitable attack, of course. -- I realize now that the corner-blocking moves that I'm generally reluctant to play - the 2-3 and, later, the 2-4 - aren't really oyose moves, they're moves that should be played as soon as it's even mildly consistent with the strength of the groups.]]

15. Kill two birds with one stone
[[ Combine pincers with side extensions, safety extensions with approaches, safety extensions with side extensions, counter-pincers with side extensions, profit with attack, expanding moyos with reducing moyos, etc. Especially important to think about your opponent's dual-purpose moves, too: for example, you might want to avoid giving him a pincer-cum-side-extension by splitting or approaching from the other side instead.]]

16. Don't touch weak stones
[[Clear enough. Two interesting points: first, after an approach-pincer-double approach (or -invasion), I think of the side I want to block on as "the side that already has an extension in place." But Otake encourages me to see that I am blighting the already weak (pincered) stone by staying away from it, whereas when I block the other way I am encouraging him to strengthen the weak stone and leaving my wall facing a light stone. Second, when you have weak stones on either side of a position, it's best, again, to make one of those non-committal shy moves (rather than leaning on, and strengthening, one weak group to have thickness to attack the other). Now strengthening either side is less of a good move, and the other side is still open to pressure.]]

17. Avoid solidity
[[This is the absolute converse of using thickness to attack. Any extension towards a solid position invites an invasion, because even a two-space extension is weak if the opponent is thick. In a sample diagram with 9 spaces between W 3-3 in the UL and black thickness in the LL, anything further than an ogeima extension invites a favorable black invasion. The fact that B has room for a "big" extension is irrelevant: the thickness was going to become profit somehow, and extending from it, even with a 4-space jump, is extremely overconcentrated. (Developing a wall from that position is ~1 pt. per stone.) Even if the opponent is not thick but merely solid, you need to hang back when trying to develop territory, because even a minimally successful invasion leaves you with nowhere to recoup the loss. This needs to be combined with the 3* line/4* line principle: if your position faces entrenched enemy stones, you can't develop ambitiously (the counter-invasion leaves you with nowhere to use your thickness), so you need to make a small extension, so you can't recoup the costs of playing on the 4* line to begin with, so you should play on the 3* line and take sente. Similar synergy with the pincer principle: if your opponent is approaching from thickness, any extension you make from a pincer is approaching thickness, so pincering ultimately commits you to making a bad move. And so on.]]

18. Thickness --> attack
[[This actually comes before "Avoid solid positions." Everyone understands the basic point, although there is a great diagram illustrating it: if there is a B ponnuki in the UR and a W high shimari in the LR, B's thickness is completely wasted unless there's a fight: if they share the side, it looks like B has practically wasted two moves. However, not all influence is thick: it the wall is short, flanked, under-cut, or has a tenuous connection the eyespace is bad and it needs an extension to become thick. Using thickness to attack means that it's much better to let your opponent make a comfortable extension towards your thickness than a narrow extension towards your unprotected underbelly.]]

19. Reduce lightly
[[Reducing lightly has two components: first, reduce lightly instead of invading deep; secondly, once you've started the reduction and forced the moyo low, "skip away". Importantly, a (strategically) light reduction has the potential to become a very sturdy invasion if the opponent is obstinate. (Think of tewari on an invasion. If you invade deep, he would never respond by expanding the moyo, inviting you to jump up: instead he would cap, and drive you towards thickness. But if you play to reduce and he tries to attack by expanding the moyo, you dive down, and that is exactly what has happened.) Otake doesn't say much about why reductions should be tactically light (e.g., he prefers the "light" trapezoid-with-ogeima to the standard trapezoid-with-keima shape). The opponent will make some territory with his moyo. He invested many stones it it, while you were playing elsewhere. The light reduction just fouls up the developmental potential of the moyo.]]

20. Abandon stones
[[Kikashi are free moves: you get some small advantage without strengthening the opponent. If you defend them you either lose sente, or worse, lose gote! That is, when the position calls for defending a key point and use your gote to defend the kikashi stone instead, you've made a huge mistake. Worst of all is when you take a forcing move and, by adding an extra stone, turn it into a target. --- However, just because a stone is forcing doesn't mean that it's not strategically crucial. Stones that allow weak groups to settle in the corner are crucial. Cutting stones can also be crucial. If you are in a position where playing kikashi forces you to defend the stone, it may be better to preserve the aji by blocking/connecting/etc. without forcing the opponent to strengthen himself.--- And as there are strategically vital kikashi, there are meaningless clumps of stones that aren't kikashi. Letting the opponent surround five shapeless stones in exchange for a clean, thick wall is far better than trying to save the clump and saddling yourself with a weak group.]]

I've tried to read this at least twice (last fall and this spring) - not with great success. I get to a certain point each time where the reading requirements are too high and the retention too low. Part of the problem is that, whereas with Davies' Tesuji you learn one pattern, and practice by applying it a dozen times, in his L&D the "pattern" itself is highly specific, and there's no particular logic to where the outside stones are in the "standard" position. Thus "the comb group is alive," assuming that the second line is completely open, but "the door group is dead," this time assuming that the second line is closed off. If the "comb" is closed off on the second line or the "door" is open on the second line, then of course it's different. --- Then, after seeing the basic life and death pattern once, the accompanying problems don't require you to spot and practice the basic pattern (which, naturally, is quite artificial) but instead to explore what happens when there is an extra liberty here, or a hane there, an extra leg there, et cetera.

This is not to complain. I still think it's a useful book. But it's much, much more encyclopedic than Tesuji, so it's no surprise that it puts harsher demands on my limited reading ability and offers less opportunity to internalize through repetition.

Maybe I should think of this less as something that I'll "learn" like one learns this many tesuji or that many joseki, but just as a complement to tsumego: on the one hand I'm trying to develop my raw reading strength, on the other I'm trying to give my reading a little technical finesse.

[Side Groups and Fundamental Techniques]
1. Unsettled Three ---- This much is obvious. But what's harder to remember is that a three-space nakade in a five- or six-space eye kills *if* the enemy group is in two string *and* has a cutting point *and* the two strings only share one liberty, *or* the enemy group only has access to one of the liberties.

2. Six die, eight live ---- Also worth remembering that when the stones are up against the corner or wrap around the corner, 5 is the unsettled shape (four die, six live). In general you want to play to enlarge the eyespace, but with the wrap-around shape you need to play the 1-1 first to avoid bent-four.

3. Four and five space eyes

4. Rabbity Six --- barring cutting points, the corner, etc., the hanaroku shape in the largest nakade, so the hanaroku +1 is the largest dead eyespace. However, there is no way to make the hanaroku inside of larger shapes, because the attacker can't occupy all the key points of the nakade in time. (Specifically, when you are imagining the nakade you will build, ideally all of the potential nakade points are already adjacent to existing stones. If there are potential nakade points that are not adjacent to existing stones, the defender can force the attacker to add stones to prevent eyes and get a seki.) But it's important to remember that if you are one or more moves ahead, you can build a lethal hanaroku inside an arbitrarily large eye.

5. One-space notchers --- A one space notcher is a string of stones on the second line with an empty triangle sticking up into the third line such that the group has one point of potential eyespace on the second line. (It is surrounded by enemy stones on the second, third, and fourth lines.) Four die, seven live, five and six are unsettled. The point that turns the notch into an eye is the vital point. For the four-point one-space notcher, of course, preventing an eye in the notch and preventing an eye on the first line are miai. For the five-point notcher, once the notch-eye has been established there is a half-eye on either side of the group. For the six-point notcher, you don't need to make the notch-eye immediately to live; descending to the first line off the longer side suffices. ------ A key technique with notchers is to make one eye, and then let the enemy figure out how he's going to prevent the second eye. This frequently involves making an eye, connecting in the notch, and leaving the attacker with no way to pull out the stones he has played under the group.

6. Shortage of liberties ---- Again, the shortage of liberties concept is familiar, but the key strategic theme is to play the vital point first, and then put the burden of making a second eye on the defender.

7. Two-Space Notchers ---- Two-space notchers are actually less secure than one-space notchers: the eyespace is one space larger, but much boxier. (For example, you can't turn the notch into a discrete eye with a single stone.) Five die, six is unsettled, seven is alive. You need at least six points to defend the weak side of the notch, then turn the notch into an eye, and still have a secure eye on the first line. Since the cutting point of the two-space notch is such a problem (unlike the one space notch, playing in the notch isn't self-atari), a six-point, two-space notcher with two cutting points is just dead: a six-point, two-space notcher with no cutting points can live by descending, instead of by guarding the cutting point.

8. Eye in the interior --------- There are two different ways to kill by making an eye in the belly. First, the eye gives you an advantage in the semeai. Second, if the group with an eye is in a nakade shape, there is neither semeai nor seki, no matter how large the eyespace is; the attacker can fill in all the outside liberties, at which point he can never be put in atari. (And so conversely, there are two reasons to prevent an eye in the belly: if the group in question could be in a nakade shape, preventing an eye is the top priority; if the group in question is in an ugly shape, you still need more outside liberties than shared liberties to kill it. This can mean, for example, that you intentionally give a group an eye in order to force a non-nakade shape that you have enough liberties to capture.) It's also worth keeping a false eye in the middle of the bulky five: if he gives atari you can connect, but that extra stone (to give atari) shrinks the eyespace, whereas if he doesn't give atari you can fill the outside liberties and then make a real eye.

9. Three-space notchers ------- The three space notcher has stones on the second, and third, lines, surrounded by enemy stones, with a three space notch. Both ends of the notch are strong, i.e. no cutting points. It is as secure as a the one-space notcher again (five and six points live or die with sente), because it loosely sketches out the living six-space rectangular eye. The vital point is in the middle of the notch, breaking the big notch into two notches; the attacker can still prevent two eyes, but cannot make a nakade shape. The six-point is the same, although the defender can live by descending. If the one end of the notch is weak but not yet cuttable (a missing enemy stone), the status is the same but making seki becomes sente for the attacker. ---- A related group is the comb formation. This is a three-space notcher with cutting points on both ends of the notch, but with two descents to the first line (and no enemy stones adjacent to the first-line stones). It is alive. (The lines of the board are the teeth of the comb, I've decided.) I think the idea is that if you have a proto-three-space notcher, it's better to descend to the first line than to strengthen the ends of the notch.

10. False eyes and placement techniques -- again, it isn't the false eyes and shortages of liberties that are quite as impressive as the strategic calm: take the vital point first, then let the enemy struggle to make/prevent a second eye.

11. The Door Group is Dead --- the door group is a string of 8 stones stretching around from the second to the fourth line, vaguely sketching out an upright rectangular six. It is dead as it stands: if the defender tries to expand the eyespace he ends up with a dead bulky five, but if he "bends in" by taking the vital point of the bulky five for himself, the attacker can hane under the bend, the defender makes an eye above the bend, and then the final stone has miai of connecting under the bend or slipping out the other way. --- However, connecting under the bend requires the attacker to make a three-stone string, which, of course, can't be in atari: so a hane out adjacent to the bend makes the group living. With one additional leg on the second line the door group can live by descending, with a second leg the door group is already alive. However, it's worth noting that even when the shape is living the attacker has the option to make a three-stone seki inside: if the corners of the door have cutting points, this seki becomes death. (I've decided that the group itself, set next to the surrounding stones of the opposite color, looks vaguely like a door that's slightly ajar.)

12. Incomplete Shapes
13. Review

14. To make one eye
15. Half eyes
16. Bent four in the corner
17. The 1-2 points, etc.
18. Placement: Attack and Defense
19. Throw-ins
20. The L Group
21. The first L+1 Group
22. The second L+1 Group
23. L+2 Group
24. Tripod Group
25. J Groups
26. Hane for ko
27. Long L group
28. Seki in the corner
29. The Carpenter's Square
30. The Weak Carpenter's square
31. More corner positions
32. Live or link up
33. Threat to capture
34. Under the stones
35. The difference a liberty makes
36. Building eye shape