Click Here To Show Diagram Code

[go]$$W Moves 14 to 14
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . O . . . . . . . . . . . . . . |
$$ | . . . O X . O . b . . . . c . . . . . |
$$ | . . . , X . . . . , . . . . . X . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . . . . 1 . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . a . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . e . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , O . . |
$$ | . . . X . . . . . . . . . . d . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Click Here To Show Diagram Code

[go]$$W Moves 14 to 14
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . O . . . . . . . . . . . . . . |
$$ | . . . O X . O . . . . . . . . . . . . |
$$ | . . . , X . . . . , . . . . . X . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . B . . . . . . . . . . . 1 . . |
$$ | . . W . a . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . B . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , O . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

This is better than any of the corner approaches or reinforcements. Preventing the marked white stone to move out, killing it instead and thereby linking up the marked stones, is the urgent move. Likewise, White should have gone out attaching at A.

I found e tempting (much more than c), but a makes sense. c doesn't make any potential and commits to the left. Normally you would consider pincer, but the right doesn't have B development either. Furthermore, W attacking the upper right could make a combination with attacking B's upper left. Hence the upper left is even bigger than it was before

The upper left corner is more alive for W than normal with more space in the corner and B is more thin, so b isn't a good idea.

Note that even after a, W seems to have ko to almost connect on the 2nd line.

I prefer playing in the bottom right corner. The fight in the upper left is even and therefore not worse than any other way to start the fight.

Sneaky! "Urgent before big" turns out to be a more urgent proverb than "corners then sides then centre" :-)

Having said that, KataGo rates 'd' or 'e' as less than a 1-point loss relative to 'a'. So nothing to worry about compared with the awful mistakes I'll make during the middlegame. Interesting too that 'b' doesn't seem to be the best local move at the top (according to KataGo again).

I haven't looked at your candidates or answer yet, but my own candidates look something like this:

Click Here To Show Diagram Code

[go]$$W Moves 14 to 14
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . O . . . . . . . . . . . . . . |
$$ | . . . O X . O . . . . . . a . . . . . |
$$ | . . . , X . . . . , . . . . . X . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . . . . 1 . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . e . . . . . . . . . . . . b . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . c , O . . |
$$ | . . . X . . . . . . . . . . d . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

My first instinct is to reply to the corner approach or make an approach of my own, but capturing that stone on the left looks really attractive. It gets a lot of solid territory, means black is unlikely to end up with any weak groups throughout the opening, and potentially sets up a huge moyo on the left. I think I'd find that too attractive to pass up; I can handle a second approach stone to a 4-4 without a huge loss.

Now I'm going to go peek at the answer and see how far off my kyu reasoning is.

Edit: Not too shabby!