what he threatenes is not big at all. i will attack his group in sente and get much out of that attack as possible and decide if i want to save that he threatened. i probably wont save them and use them as aji.
below is what i expect for next few moves. i love my influence growing like an avalanche.

Click Here To Show Diagram Code

[go]$$Bcm51 Prisoner Count: B-0 W-0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . 6 O O O . . . . . . . . . |
$$ | . . . . . 8 5 X X O X . . . . . . . . |
$$ | . . O , 0 9 . . . X O X X . X X . . . |
$$ | . . . . . . . 7 . X O O X . . O . . . |
$$ | . . X . . . . . . X . . . O . . . . . |
$$ | . . . O . . . . . . 4 O X O . X . . . |
$$ | . . X X O . . . . . . . . . . . . . . |
$$ | . . X O . O . . X . . . O . . . . . . |
$$ | . . X O . . . O . , . . . . . , X . . |
$$ | . . X O . X . . . O . . O . X . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

ok...i guess i answered his move without thinking..
if i had time to read..i wouldnt have answered that.

Why not continue if you're going to play in the first place?

Click Here To Show Diagram Code

[go]$$Bcm51 Prisoner Count: B-0 W-0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . O O O . . . . . . . . . |
$$ | . . . . . . . X X O X . . . . . . . . |
$$ | . . O , . . . . . X O X X . X X . . . |
$$ | . . . . . . . . . X O O 3 . . O . . . |
$$ | . . X . . . . . . X . . 4 O . . . . . |
$$ | . . . O . . . . . . 5 O X O . X . . . |
$$ | . . X X O . . . . . . . . . . . . . . |
$$ | . . X O . O . . X . . . O . . . . . . |
$$ | . . X O . . . O . , . . . . . , X . . |
$$ | . . X O . X . . . O . . O . X . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

It would be aji-keshi, I think. It would be unlikely for white to remove that possibility, so playing it now at least loses a ko threat.

I would probably play 55 as hyperpape suggests (but maybe it is bad). I wouldn't call wasting a ko threat aji keshi. Aji keshi is removing your other possibilities in a position. The only other plausible choice I see for black here is the throw in at m8 first and then l7 which reduces white's liberties by 1. The downside is black also loses the l8 liberty. As white is super strong and connected I don't see removing 1 white liberty to be useful, and black losing the l8 liberty is a big minus. Thus I think l7 is the only choice black would want here so it's ok to play it now. Indeed black had better make sure he gets it before white possibly captures L11.

never attack group you can not kill.

Isn't it fair to say sometimes you attack (or press at least) a group to get strong enough to attack something you _can_ kill?

I even hear a lot of strong players saying, that one should never attack with the thought to kill, but to take advantage.

Reminded me of my favourite lesson from back when I was trying to get stronger.

"Now his methods were patterned after a steady infantry advance, which gains ground and takes time to consolidate its gains, even if that means letting the enemy survive. He started to win more often, and his rating went up. He still occasionally brought down a large group - some of his opponents simply refused to see the need to defend, and others had an outright death wish - but these successes no longer mattered much to him, for he had learned to exchange the pleasure of making the enemy die big for the subtler pleasure of making him live small" [Akira Ishida and James Davies: Attack and Defense]

Of Marcus' sequence, I'd want to keima at 64.

Click Here To Show Diagram Code

[go]$$Bcm61 Prisoner Count: B-0 W-0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . . . O . . . . . X . 6 . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 4 . . . . . . . . . . . . . . . . |
$$ | . a . . 2 O O O O O . . . . . . . . . |
$$ | . . 5 X 3 X X X X O X . . . . . . . . |
$$ | . . O , . . . . . X O X X . X X . . . |
$$ | . . . . . . . . . X O O X . . O . . . |
$$ | . . X b . . . . . X . O O O . . . . . |
$$ | . . . O . . . . . . X O X O . X . . . |
$$ | . . X X O . . . . . . . . . . . . . . |
$$ | . . X O . O . . X . . . O . . . . . . |
$$ | . . X O . . . O . , . . . . . , X . . |
$$ | . . X O . X . . . O . . O . X . . . . |
$$ | . . X X O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

If black cuts of the white stone with 65, I'd attack the black stone on the top with 66 and I'd still have aji the play at a and b to make use of that stone.

I'm not sure how much aji there is at "b" whilst Black can cut that stone off ... one to the right of "b" maybe.