BillSpightsElfPositionalJudgmentExercises/Game 3 ELF's Solution

Go Seigen (W) - Sakata, no komi  

According to Elf, both players made a number of small mistakes early in the game, which may be explained by the shared beliefs about the opening at the time. The first sizable mistake was , which may have also been a mistake with no komi.

Failure to sacrifice? Loss of 20%  

caught me by surprise. When I was learning go the sacrificial hane at 20 was joseki. It appears that allowed White to make too much outside strength with .

Sacrifice. Main line.  

The ladder works now, but Black has many ladder breakers near the stones.

Main line, continued  

At the time, 25 was usual, but today's bots have devalued the sides.

is good shape. a would allow a double peep.

Failure to sacrifice, loss of 12½%  

According to Elf, loses 12½%. OC, the subsequent fight is complicated, and there is no komi, so was not necessarily a mistake.

Sacrifice variation  

This sacrifice lowers White's winrate estimate to 80%.

Elf's continuation, II  

White sacrifices the corner for central strength. :)

Knotwilg's idea  

Elf considers Knotwilg's idea for and gives the above variation, with pushing into the corner. Next if Black a, White b, I reckon.

The remaining diagrams show the continuation in the actual game.

Actual game continuation  

The fight continues into the center. severely attacks Black's small group in the top right.

Small life, but with sente  

Since Black lives with sente, he manages to put some pressure on White.

White starts to develop the right side  

White pushes on into the right side. the center battle continues. Elf gives Black a 2% chance to win. Go Seigen won by resignation after White 234. (Sakata hated to resign.)