BillSpightsElfPositionalJudgmentExercises/Game 16 ELf's Solution

White is ahead  

Black's bad shape, the empty triangle on the bottom side, is a clue. However, Kato, who was no slouch, had just played to create it. Perhaps he thought that would connect at a. If so, he was right, O Rissei did play at a. Elf disagrees. It regards as a blunder, costing 19%.

Elf's mainline variation for  

is big, enlarging White's right side moyo. Instead of replying to White turns to the top side, making a three stone wall. Next, the cut at is big. is interesting, avoiding an extension towards the right, which would not have a good follow-up to its right. approaches the top right enclosure. It may also be considered as an extension from the three stone White wall. OC, the bots do not care about the human rules for such extensions. ;)

Earlier in the game

loses 13% versus a  

Elf regards as a mistake, preferring the simple and strong push at a.

Elf's mainline variation for  

After White turns to the top left corner, making the three stone wall. White replies to with a kick and jump. The fact that is high suggests that White is looking to attack and .

Elf's mainline variation for , continued  

plays the Go Seigen/AI shoulder blow against the top right enclosure. takes advantage of White's high posture in the bottom left corner to play a submarine attack. and play a counterattack against the stones.

The actual game continues.

Mutual misunderstanding  

Elf estimates that loses 15½% to par. returns the favor, losing 17½%. This kind of exchange of nearly equal mistakes suggests a shared misunderstanding of the position.

Elf's mainline variation for  

stands instead of cutting off the stone. OC, cutting off the stone shows fighting spirit, and is consistent with ( ). Not to cut off the stone suggests that was a mistake. Elf would agree. ;)

and push along the fifth line, forming a center facing wall, before connecting with . jumps along the fourth line and thenW24 connects. In effect, Black has forced White to "crawl" along the fourth line. According to traditional go wisdom, that is ill advised. However, the bots ofter prefer to make center facing walls on the fifth line in exchange for the opponent's edge facing walls on the fourth line. The bots have a lot to teach us about center oriented play.

Elf's mainline variation for , II  

approaches White's small moyo on the right side. The resulting sequence illustrates Elf's light, flexible play. on the 5-5 threatens to cut off or to invade the Black enclosure. invades the White moyo. OC, Black's fifth line wall offers support for this invasion. separates and , attacking both. jumps out into the center and then defends the White territory. Finally, defends the Black position in the top right.

Elf's mainline variation for , III  

builds the three stones wall on the top side. Then attacks it while extending on the side. bolsters White's position in the top right and then defends his invasion. takes the double keima, then and push and cut, and the opening fight continues.

Next we look at Elf's variation for in the actual game

Elf's mainline variation for  

The stand, , looks right and left, taking aim at the stones and at White's weakness in the bottom right. threatens the one and then threatens the other. is a strong riposte, cutting Black in two.

Elf's mainline variation for , continued  

turns to attacking the Black corner. shores up a White weakness and threatens to play at a. and secure the Black group.

Back to the game.

Overplay  

may be a tesuji. but Elf indicates that it is an overplay, losing 13½% to par.

Elf's mainline variation for  

is a solid play, but gote. The checking extension, , is big. approaches the bottom left corner. White replies with the footsweep, , as hinders White's development on the bottom side. is an interesting play, threatening to save , as well as to invade the right side. White now turns to develop the top side, as we have seen above.

Back to the game.

 

threatens the stones, but it is a blunder. According to Elf it loses 30%. :shock:

Elf's mainline variation for  

=

is typical when Black does not need to play at a. In this position, White does not answer in the corner, but pushes in the center. After the now rare slide, , White plays the hane, , and protects, forming a table shape. Next, White forms a three stones wall on the top side. Then jumps into the center.

Attack and Kill Kato blundered on the bottom side with a strong local attack, accepting bad shape in the process. He probably assumed that O Rissei would save his two stones, which he did, making his own blunder. We warn beginners against overvaluing a few stones. It just goes to show that even 9 dans can sometimes make kyu level plays.