I'm white. My opponent doesn't play on KGS, but he plays even with the 5k-7k players of my club. We didn't finish the game, but I'd like to know if he had means to save his central group. The opening was a little strange, with lead to some difficult decisions for me (and likely for him) to take concerning direction of play. I'dlike comments on these (from both point of view).

Feel free too to criticize anything, be sure I'll feel free to ask for explanations

7 - extremely unusual. I don't think there's anything necessarily wrong with your response for 8, but F18 looks simpler and more efficient.
14 - You *must* play G16 here to capture the two stones in a ladder. E14 was a critical mistake by Black.
22 - There is some aji at D17, sure, but a better way to take care of it is to play B14. This not only threatens the snapback at D14, but if Black plays the cut ourright at D17, you can play D18 and you are fine (D17, D18, C17, B18). Note the difference that B14 makes.
24 - Mistake; the unusual move of P5 does have clear meaning (to capture F15 in a ladder). You must play F14; not only does it keep Black's two groups on top separated, but Black's C15 group will be painful for shape.
42 - The approach is big, sure, but Q5 feels slightly bigger.
50 - I would sacrifice the 3 stones here by playing L10; attacking this group is not easy when you have to worry about the cut at both J14 and J11. L10 also builds central influence and isolates P5. It is also a simpler strategy; therefore L10 feels better.1
52 - Must Q12; White's shape on the left group will be in shreds if Black plays Q12.
80 - Insipid; N10 is better because it puts more pressure on Black's group.
120 - C7 is a ko; C7, E8. In fact, B8 is the faulty move here, but Black played incorrectly. After Black forces with E8 (which he does), Black can play B7 and kill the 3 stones. Unfortunately for you, Black manages to kill B8 and is in good shape until he loses his bottom dragon.

Here's my 1k perspective .

_________________
We don't know who we are; we don't know where we are.
Each of us woke up one moment and here we were in the darkness.
We're nameless things with no memory; no knowledge of what went before,
No understanding of what is now, no knowledge of what will be.

Just looked up 7 in the database, surprisingly there is a (yes, only 1 found in the database) professional game where it was played (in early stage). Fortunately my suggestion is what the pro played:

Wow Araban, that is one fascinating, complicated fight.

_________________
We don't know who we are; we don't know where we are.
Each of us woke up one moment and here we were in the darkness.
We're nameless things with no memory; no knowledge of what went before,
No understanding of what is now, no knowledge of what will be.

Thanks for your comments, they are very enlightening.

There are comments I was expecting, since I realized some mistakes during or when replaying the game (such as the 5-5 ladder breaker), others I didn't see at all (noticeably the fact that the ladder at 62 was good. I really feel ashamed I made this mistake )

Thanks too for your thoughts on the moves around the stone on the tengen, I felt it was a mistake but it really was a situation that doesn't occur frequently in my games, and I felt a little lost.

I think of the ladder-breaker this way: Any stone along that wide diagonal is going to be a ladder-breaker. How can you know where the best spot is to play? You can't. So, wait until it becomes obvious where a good spot to play is before playing it. It could be that you play it in the midst of a complicated fight and he simply cannot afford the time to go back and capture those two stones. Ladders offer very good aji to the opponent, which is often why you see pros capture them even if the opponent hasn't played a ladder-breaker yet.

_________________
We don't know who we are; we don't know where we are.
Each of us woke up one moment and here we were in the darkness.
We're nameless things with no memory; no knowledge of what went before,
No understanding of what is now, no knowledge of what will be.

Would any stronger players mind helping me out a little? I absolutely can't understand moves 79, 80, 81, 82, and 83.

It looks like white can sacrifice three stones with 78 to get a couple of points in the corner. Then black misreads and thinks he can capture the whole thing. Then white misreads and fails to punish black's overplay. Then black doesn't play the obvious atari and makes it into a capturing race which he loses. Then white forgets to make it a real capturing race before taking liberties inside. Then black realizes he doesn't have two eyes on the left if he doesn't win the capturing race -- except that he can win the capturing race WITH A SIMPLE ATARI.

These are professionals, not 17 kyu players, so I assume one of two things has happened:
1) I am blind, ignorant, stupid and ugly.
2) the game record is incorrect as to the order of moves.

Could somebody help me out and tell me which of these is the case?

Well, fortunately for you, it's not 1 . Since you mentioned it I decided to look over the game and did find something was off. I checked with another source, go4go, to see if their SGF was consistent since this game was a Samsung cup game, so I figured there would be more than one database out there that had this game. Turns out the game record is, in fact, incorrect. The mistake roots all the way back to the beginning at move 7; in fact, 7 wasn't played as is but instead they played the avalanche.

Go4go has a copyright lock on this SGF, but you can view it in their web applet here to see what I mean:
http://www.go4go.net/v2/modules/collect ... hp?id=7725

Aha! Now it makes sense. Otherwise the corner is completely incomprehensible, since it seems that for 100 moves, whoever wants can take the corner.

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A good system naturally covers all corner cases without further effort.