定石 Research Part 3

基本图
黑1 cuts directly without atari (R15) gives black an option to capture marked white seed with A.

If 白2 长 to 白4 this variation looks somewhat like another variation (right).

Key differences: Left variation

1. Black has more territory. Although some bad aiji marked white seed can not live right away in the corner.

2. Exterior white group feels thinner and weaker.

Therefore, 白2 is probabily not a good option.

黑1-黑5 is probabily 一本道 next white needs to prey the brain and think about how to fortify cuts outside.
黑4 is too severe thus 白1 capture is not a good option.

After 黑2 join, corner territory is quite big plus not much of aiji. Although white gains sente (original joseki white is gote) black peeks at A is a bit annoy.

For original joseki, white has a nice yose move at 白1 when white has marked seed. 黑2 is 本手. White reduces black corner's territory by tightening black group's liberties.

黑: 张亚博 白: 柁嘉熹 July 01, 2009 白+

黑37 is a bit of overplay. 白44-52 impressive sequence of tesuji moves.

白1 is the easiest to think so but white group is a bit heavy especially after black peeks at A. Corner white seed can't pull out as white doesn't have enough liberties.

白1 is an interesting move. If black carelessly responds with 黑2 then 白3 capture becomes sente. White can be satisfied with this variation.

Sequence up to 白5 is a possible variation. Personally I prefer black a bit more.