Apologies if I've posted in the wrong forum. White invaded during sente with this C6 move. I feel I should've handled this stone when I had sente. Is it possible to destroy these stones? In the game, I failed to kill them.
Had black played at C6 a few moves before, instead of white, black would definitely have been strong enough to kill. I suspect (though I can't say for sure without looking at the record) that there were a few smaller moves played before white tried this. Even as it is, it's not clear that black needs to kill white to win. If black can limit white to a small group, white's other group is also pretty small and he may have enough to win that way.
$$B $$ --------------------- $$ | . . . . . . . X . | $$ | . . 2 1 . . . . X | $$ | . . O . . . X X O | $$ | . 4 O X . . X O O | $$ | . 3 . . X X O O . | $$ | . . . . X O O . . | $$ | . . X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ --------------------
[go]$$B $$ --------------------- $$ | . . . . . . . X . | $$ | . . 2 1 . . . . X | $$ | . . O . . . X X O | $$ | . 4 O X . . X O O | $$ | . 3 . . X X O O . | $$ | . . . . X O O . . | $$ | . . X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ --------------------[/go]
In a situation like this it is useful to know a few basic proverbs. The one I am thinking about here is "The L-group is dead". EdLee applied this to show you the solution but if you had known it yourself then the moves would immediately jump out at you. This proverb is one of the most useful there is when it comes to corner invasions.
Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).
I'm wondering what the black move was before white's last one at c6. Although killing now is still plausible, if black plays the previous move better then killing should be super easy.
But you are right: depending on situation, making L-group can be useful. In addition to ko threats, capturing races come to mind. Though "dead", the L group has many liberties.
$$W $$ --------------------- $$ | . . . . . . . X . | $$ | . . . B . . . . X | $$ | . . O . . . X X O | $$ | . . O X . . X O O | $$ | . . . . X X O O . | $$ | . 1 . . X O O . . | $$ | . . X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------
[go]$$W $$ --------------------- $$ | . . . . . . . X . | $$ | . . . B . . . . X | $$ | . . O . . . X X O | $$ | . . O X . . X O O | $$ | . . . . X X O O . | $$ | . 1 . . X O O . . | $$ | . . X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------[/go]
$$W $$ --------------------- $$ | . . 0 . . . . X . | $$ | . 4 9 B . . . . X | $$ | . 5 O . . . X X O | $$ | 7 . O X . . X O O | $$ | . 3 2 . X X O O . | $$ | 8 1 . . X O O . . | $$ | . 6 X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------
[go]$$W $$ --------------------- $$ | . . 0 . . . . X . | $$ | . 4 9 B . . . . X | $$ | . 5 O . . . X X O | $$ | 7 . O X . . X O O | $$ | . 3 2 . X X O O . | $$ | 8 1 . . X O O . . | $$ | . 6 X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------[/go]
Can B do better than ko ?
$$Wm11 $$ --------------------- $$ | 2 1 X . . . . X . | $$ | 3 X O X . . . . X | $$ | . O O . . . X X O | $$ | O . O X . . X O O | $$ | . O X . X X O O . | $$ | X O . . X O O . . | $$ | . X X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------
[go]$$Wm11 $$ --------------------- $$ | 2 1 X . . . . X . | $$ | 3 X O X . . . . X | $$ | . O O . . . X X O | $$ | O . O X . . X O O | $$ | . O X . X X O O . | $$ | X O . . X O O . . | $$ | . X X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------[/go]
$$W (a), (b) miai life $$ --------------------- $$ | . 6 . . . . . X . | $$ | 7 5 4 B . . . . X | $$ | . a O . . . X X O | $$ | 9 . O X . . X O O | $$ | . 3 2 . X X O O . | $$ | b 1 . . X O O . . | $$ | . 8 X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------
[go]$$W (a), (b) miai life $$ --------------------- $$ | . 6 . . . . . X . | $$ | 7 5 4 B . . . . X | $$ | . a O . . . X X O | $$ | 9 . O X . . X O O | $$ | . 3 2 . X X O O . | $$ | b 1 . . X O O . . | $$ | . 8 X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------[/go]
$$W $$ --------------------- $$ | . 4 6 . . . . X . | $$ | . 7 5 B . . . . X | $$ | . . O . . . X X O | $$ | . . O X . . X O O | $$ | . 3 . . X X O O . | $$ | 8 1 . . X O O . . | $$ | . 2 X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------
[go]$$W $$ --------------------- $$ | . 4 6 . . . . X . | $$ | . 7 5 B . . . . X | $$ | . . O . . . X X O | $$ | . . O X . . X O O | $$ | . 3 . . X X O O . | $$ | 8 1 . . X O O . . | $$ | . 2 X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------[/go]
$$W $$ --------------------- $$ | . 0 8 . . . . X . | $$ | . 4 7 B . . . . X | $$ | 9 5 O . . . X X O | $$ | 6 . O X . . X O O | $$ | . 3 2 . X X O O . | $$ | . 1 . . X O O . . | $$ | . . X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------
[go]$$W $$ --------------------- $$ | . 0 8 . . . . X . | $$ | . 4 7 B . . . . X | $$ | 9 5 O . . . X X O | $$ | 6 . O X . . X O O | $$ | . 3 2 . X X O O . | $$ | . 1 . . X O O . . | $$ | . . X X . X O . . | $$ | . . . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------[/go]
$$W $$ --------------------- $$ | . X X . . . . X . | $$ | . X O X . . . . X | $$ | O O O . . . X X O | $$ | X . O X . . X O O | $$ | . O X . X X O O . | $$ | . O . . X O O . . | $$ | . 1 X X . X O . . | $$ | . 2 . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------
[go]$$W $$ --------------------- $$ | . X X . . . . X . | $$ | . X O X . . . . X | $$ | O O O . . . X X O | $$ | X . O X . . X O O | $$ | . O X . X X O O . | $$ | . O . . X O O . . | $$ | . 1 X X . X O . . | $$ | . 2 . X . X O O . | $$ | . . . . X X X O . | $$ ---------------------[/go]