Sunday, October 21, 2007

Writing some narratives

So far I'm doing well on level 40, but there are some problems where I'm just drawn to the wrong solution every time. So I'm taking a page out of the BDK and Temposchlucker play books and I'm going to write some narratives about these positions.

CT-Art 734:
White to Move

In this position there are two possible squares for white to invade with a knight, f6 and f5. The defenders of these squares are removed by 1. Rxh5 gxh5 and then either
a) Nd5 followed by Nf5 or
b) Nf5 followed by Nd5 and Nf6.

I'm always attracted to option (a), which is not correct. It appears correct because 2. Nd5 exd5 3. Nf5 attacks the queen and the queen cannot defend the mate on g7. However, this idea overlooks 3. ... Be3+ followed by Qxg5 (or Qe6 if Nxe3).

Option (b) is a winner because the bishop check on e3 doesn't interfere with the knight on f6 or the attack on h7. The queen is also unable to defend h7. So, 2. Nf5 exf5 3. Nd5 Be3+ 4. Kb1! Qxg5 5. Nf6+ Qxf6 6. Qxf6

One of the bottom lines is that h7 is weaker than g7 due to black's ability to get the queen to g5. This makes f6 the right square for a knight rather than f5.

I've got a few more of these to write...

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10 Comments:

At 3:07 PM, Anonymous Samuraipawn said...

I think creating narratives seems like a great technique to understand how tactics work and to find solutions. It's so easy to just start guessing when you reach up to the more difficult problems, which is both ineffective and time consuming.

I think I'll go through all the tactics I never really got in the same after I'm done with the circles. Very instructive narrative, thanks!

 
At 10:17 PM, Blogger Loomis said...

Glad you liked the narrative, hopefully I'll nail this problem the next time through. Unfortunately, it wouldn't be practical to write this much narrative about all 1209 problems, but problems that elude me after 5 repetitions are good candidates for needing good explanations before I get them.

 
At 2:59 AM, Blogger transformation said...

thank you for your comment at BDK's post, about caution in incepting a viewer AND saying your are really getting into making diagrams. ditto.

each viewer has massive problems. why can't somebody just do it, is beyond me. the best one i found, which tempo helped me sort out today over many emails, for me, becomes just a collapse, because evidentally you have to host the pgn seperate from the viewer at your blog.

so eventually, he shows me how even my 3rd tier broadband ISP (long story, non-compete required by comcast regulators, so they 'spun off' my neighborhood since diverse poor people are enmass near by...) allows you to have your own webspace, but then THEY tell you you need some tool to enable that, and so on.... and they dont really provide so much as allow it, if you follow. pay geocities money for THAT??

i will probably make more diagrams, hold up on my current version, and sort out if this fix he kindly and most generously placed into resolution offers enough benefit to try for it, instead of chess.com. yikes.

warmly, dk

 
At 4:41 AM, Blogger Temposchlucker said...

The queen converges with one knight on g7 and with the other on h7. According to Vukovic that are your focal mating points (what I call invasion squares). f6 and f5 are your auxiliry focal points. Notice how often in such problems it is the queen who delivers the final mate. The reason for that is that the queen can cover two different colors at the same time (g8 and h8) while the knight and bishop cannot. The rook can, but is somewhat clumsy in a crowded situation.

As usual the counterattack we talked alot about in the past is causing trouble. Avoiding the counterattack decides between the to focal points.

What I often do is to change the position a little, by blocking the black bishop or so, and then look if Rybka scores both knight moves equal. In that way, a lot of subtleties often can be discovered.

 
At 10:29 AM, Blogger Loomis said...

DK: I've always been wary of ISP's providing data hosting. That's not really their job. I pay my ISP to connect me to the internet and that's it. If I'm hosting data with them and a competitive faster and cheaper service comes along what happens? Or what if I move? I'm sure I can transfer all my data, but if the URL of the data is changed, everything linking to it is now broken. It feels like a bad scene to me to mix up these two services.

Tempo: Thanks for the lessons in lingo. I fear I will always get terminology wrong. The difference between an auxiliary focal point and an invasion square seems like a fine line.

I should try changing the bishop and checking with a computer. My own evaluation is that the square that was wrong with the bishop attack will become the much superior square.

 
At 12:54 PM, Blogger Blue Devil Knight said...

Chesspublisher.com has very good and free chess game viewers that are good for blog implants. It is easy: just enter the pgn, click a button, and it gives you the code to insert in your blog. See an example from Liquid Egg Product.

DK you are old school. Why publish like it's a book when it's the web? Do you not realize how lazy people are? Also, I don't understand what you think is wrong with chess.com: it is extremely simple, has good features, and is free. But there are other options.

But that said, I agree that diagrams can be good. They are obviously all that is needed for tactical puzzles, or to highlite one part of a game like you (DK) did in your recent post. It is more of a problem when someone dumps an entire game in pgn and says something like "if you want to see it, copy, go to this web site, register, confirm registration, login, kill your favorite pet, copy again, go back to web site, login again, paste, and scroll through the game."

There are tons of possibilities out there. Dating around is not frowned upon. The thing to do is try them and see what you like, not discuss endlessly which is best. If the worry is that it takes a ton of time to learn, chess.com and chesspublisher.com are both painless. Tempo will be glad to help you if you have any problems. :)

 
At 1:14 PM, Blogger Blue Devil Knight said...

By the way, thanks for the narrative. I've printed it out and am bringing it to lunch as I don't understand it yet.

 
At 1:18 PM, Blogger Loomis said...

You're welcome of course, and I hope you got Tempo's comment on your print out.

I just looked at the position again and I think that moving a pawn from f3 to f2 might change the solution in the interesting way that Tempo alluded to, but I'll have to check that later.

 
At 1:44 PM, Blogger Temposchlucker said...

Blue,
thanks for giving my time away:)

Loomis,
it were those tiny differences in the position with such great impact that made me realize that it is not the recognition of geometrical patterns that we are after but more the recognition of the essence of a position. A narrative is a tool just for that.

 
At 2:16 PM, Blogger Blue Devil Knight said...

That is a tough problem, not least of which because it taxes my visualization skills. If I were to use my solution-focused method on these problems it would probably take me a good 20 minutes per problem to feel like I got the essence (and that assuming I spend less than two minutes starting at the initial problem).

This one is nice as it forces you to consider defensive resources. I didn't consider the right move because I didn't think through the removal of the guard sub-tactics involved.

 

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