Four die but six live / analysis

Six stones on the third line live  

When Black has six stones in a row, White can not kill the stones. - fails after .

Bill: doesn't look too good to me. How about white a or white b?

SGBailey: ' at a appears to be handled by ' between a and 6. There are potential throw-ins and other complicated stuff depending what path White wriggles with.

Death  

Bill: I think White can kill, then.

Seki  

Bill: Black can make ko, but seki is normally better, no?

Life  

Bill: (Much later.) lives, doesn't it? and are miai.

torij?: Actually, if white wants to do something it is better to play at and make a gote seki. Since playing here is gote for either side, black most like as not lives in endgame.

Robert Pauli: torij, it's a sente seki (see main page).

Life  

SGBailey: ' at b gets ' at a.

Bill: Right. :-)
seems to be White's best play.

Robert Pauli: No, torij was right.

Invasion  

Bill: No. is the key point. captures the stones.

White keeps sente  

Robert Pauli: should connect. This results in the seki shown here, with White keeping sente, not loosing it. That's certainly worth a point less.

White keeps sente?  

Bill: But if Black now plays ?

Robert Pauli: White pushes ahead on the second line, not? If there's no escape, nothing has changed essentially (besides that pushing from behind is bad).

5 dies  

zephi? Unfortunately, 5 on the 3rd line dies even if b has sente. After 6, b can't get 2 eyes. (note: playing b5 one space to the left doesn't work either)

5 dies  

nachtrabe: Sure that isn't a seki?

Chris Hayashida: at ? Then when the outside liberties are filled, White can atari from the inside and make a bulky five shape, killing Black.

kevinwm: The shape shown first is a sente seki for w. Playing 6 at 7 makes it death. Stones 8 and 9 below are miai for seki.

Aim at the vital point first  

torij?: The gote move of 4 in SGBailey's diagram seems to be the wrong approach. Aiming for the vital point before playing a hane is key. Black has a difficult time answering this because 'a' becomes a ko and anything that doesn't reduce white's liberties will allow white to play 'b'.

seems alive  

hnishy: live by oshitsubushi ( at a), isn't it?