What do I have to do just to get to 5k?

schawipp · Post by **schawipp** » Sun Aug 14, 2016 12:40 pm

EdLee · Post by **EdLee** » Sun Aug 14, 2016 1:30 pm

Fedya · Post by **Fedya** » Mon Aug 15, 2016 12:28 pm

Since we've discussed the previous problem to death (no pun intended), here's one that showed up today:

Click Here To Show Diagram Code: [go]$$Bc Black to play $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . X X X X . X . . $$ | . O O O O O X . . $$ | . . . . . . X . . $$ | . . . . . . . . . $$ -------------------[/go]

Enough lucky guesses and you'll get Black 1; you'll need to go farther than that. (Needless to say, this is one I couldn't figure out.)

DrStraw · Post by **DrStraw** » Mon Aug 15, 2016 12:40 pm

Knotwilg · Post by **Knotwilg** » Mon Aug 15, 2016 1:19 pm

I remember I found this problem quite hard.

I'll try solving it again.

Approach:

Bill Spight · Post by **Bill Spight** » Mon Aug 15, 2016 2:27 pm

A review of your recent tournament game. Congratulations on your win!

Also, I got the sense that you played up to yourself in this game. Do you think so, too? If you play up to yourself you can beat 5 kyus.

Perhaps the slow pace of a turn based server is good for your learning.

You played a steady game and did well in the endgame.

One thing I sensed in your play is that you think about what your opponent can do to your groups, but you do not seem to think much about what you can do to his. You missed opportunities to attack his group in the bottom right, and especially to attack his group on the bottom side. Also, in the endgame you failed to see your threats against his group in the top right corner. Strive to become a dangerous opponent. Let them worry about what you will do.

If you play up to yourself and learn to attack, there is no reason you can't reach higher than 5 kyu, even without much in the way of technical improvement. (OC, attacking will present new problems for you over the board, which you will learn to handle.)

Fedya · Post by **Fedya** » Mon Aug 15, 2016 5:06 pm

A few quick comments on Bill's review:

1) Apparently I need to learn about capping the tree. When I see an attack that far away, it looks to me as though the other person is going to escape, and I'm reminded of Ed Lee's (I think it's him) persistent comments about squeezing the toothpaste.

2) All those moves you described as aji keski were moves that I played because I didn't want White to play there! I didn't think any of them were bad!

3) T13 was one of those endgame moves I debated over but rejected because I figured while it gained me a point, White didn't need to respond right now, which means White could play all those one-point sente moves to which I would have to respond immediately. Granted, the move that I picked still wasn't the best alternative. (It was also two points, which is more than the one point at T13.)

I was also glad that the game didn't come down to winning the one-point ko at F16.

I may have more comments later.

Bill Spight · Post by **Bill Spight** » Mon Aug 15, 2016 6:39 pm

Fedya wrote: 3) T13 was one of those endgame moves I debated over but rejected because I figured while it gained me a point, White didn't need to respond right now, which means White could play all those one-point sente moves to which I would have to respond immediately. Granted, the move that I picked still wasn't the best alternative. (It was also two points, which is more than the one point at T13.)

You may verify that T-13 gains 3 points for Black, not 1.

Fedya · Post by **Fedya** » Tue Aug 16, 2016 12:14 pm

If Black plays T13, White loses the point at T14 and one other to fix the weakness, but I don't see a third point.

I was counting so much mostly because I could tell the game was so close. If I had counted and concluded I was up 10 points, I probably wouldn't have counted so much. I don't count so well over the board because when there's a clock running, it's much more difficult.

mitsun · Post by **mitsun** » Tue Aug 16, 2016 1:00 pm

Fedya wrote:If Black plays T13, White loses the point at T14 and one other to fix the weakness, but I don't see a third point.

Endgame calculations depend critically on sente/gote considerations. You are assuming that W answers every B move, letting B make two points in sente. That is not correct play for W. Normally W should treat the inital B move as gote and not respond, since there are bigger moves elsewhere on the board. This leaves a one-point sente play for B (or equivalently a one-point reverse sente play for W). The usual assumption is that B will get to make this play in sente before W finds it profitable to play as gote.

Fedya · Post by **Fedya** » Tue Aug 16, 2016 1:48 pm

I wasn't the one making that assumption. I said that I didn't play T13 because I didn't think White needed to respond to it immediately, and that White would respond by playing the moves I did need to respond to immediately. And it's Bill that's saying it's worth three points, not me.

[sits back and watches whether the high dans start arguing with each other, hoping to be able to learn something from it....]

dfan · Post by **dfan** » Tue Aug 16, 2016 2:21 pm

The situation as of move 188:

Click Here To Show Diagram Code: [go]$$B $$ . . X X O . . | $$ . . . X O . . | $$ . . . . X O . | $$ . . . . X O . | $$ . . . . X O . | $$ . . . . . X X | $$ . . . . X O O | $$ . X X , X X O |[/go]

If White goes first:

Click Here To Show Diagram Code: [go]$$W $$ . . X X O . . | $$ . . . X O . . | $$ . . . . X O . | $$ . . . . X O . | $$ . . . . X O 1 | $$ . . . . 2 X X | $$ . . . . X O O | $$ . X X , X X O |[/go]

White has 6 points and played it in sente.

If Black goes first, White has a choice. He can defend immediately:

Click Here To Show Diagram Code: [go]$$B $$ . . X X O . . | $$ . . . X O 4 . | $$ . . . . X O . | $$ . . . . X O 2 | $$ . . . . X O 1 | $$ . . . . 3 X X | $$ . . . . X O O | $$ . X X , X X O |[/go]

He has 4 points and Black did this all in sente.

Or he can say "Black's followup is small, so I don't think

is sente", and play elsewhere on the board. Later Black comes back and makes that small followup:

Click Here To Show Diagram Code: [go]$$Bc :w2: elsewhere $$ . . X X O . . | $$ . . . X O 6 . | $$ . . . . X O 4 | $$ . . . . X O 3 | $$ . . . . X O 1 | $$ . . . . 5 X X | $$ . . . . X O O | $$ . X X , X X O |[/go]

Now White has 3 points but Black's play was gote (he has made three moves in the area, while White only made two).

So the play for Black is 3 points in reverse sente. At least that is my 4k reading

mitsun · Post by **mitsun** » Tue Aug 16, 2016 2:25 pm

I am agreeing with Bill -- the B play under consideration is worth 3 points in gote.
What sequence gives it a value of 2 points? Would that sequence occur with proper play?

Kirby · Post by **Kirby** » Tue Aug 16, 2016 2:34 pm

In endgame, there is the concept of "privlege". If black makes a play, of course, white can ignore. But if black's play is sente, but white's play is not, then black has the privilege to play there, and we can assume he will.

So if black plays T13, white's immediate local response is gote, whereas black's is sente. Therefore, we assume that if black plays T13, he will also get T14, since it's sente. So black T13 also includes T14.

If white plays first, it is sente, and white gains 3 points compared to if black has T14.

Fedya · Post by **Fedya** » Wed Aug 17, 2016 12:20 pm

This discussion has certainly been interesting and edifying. Indeed, part of the reason I posted that particular game is because I was looking for that sort of discussion about the endgame, regarding an actual game and not just contrived problems.

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