tagging questions

[texian]

STUMPED AGAIN

i am really clueless about this one 42971 for both the tag and the solution .. i ran the setup in Fritz and the CT solution was confirmed as the best choice, better even than Fritz, but i can't see how Black's response, a queen sacrifice, makes sense .. i suspect that if the problem were setup from Black's perspective it would be a very highly rated problem

i'm beginning to feel as if i am getting anally analytical, but i actually find this fun, for now .. hopefully, i'll get over it soon

regardless, the problem begins with White up a bishop [W:B+], Black up a knight [B:N+] appearing fairly balanced .. here is the analysis on three lines with the Fritz evaluation and piece balance after 4 moves:

CT line 1. Bf3 Nxg3 2. Bxe4 Nxe4 3. Re1 Ng5 4. Nd5 Nc6 (4.22) [W:Q+] [B:B+ N+]

Fritz line ... ... 3.Nd5 Nc6 Re1 Ng5 (4.41) [W:Q+] [B:B+ N+]

Alternate 1... Qe7 2. Nd5 Qg5 3. Bxb8 Ra8 4. Bf4 Qh4 (6.38) [W:B+]

in my alternative, thinking Black should NOT sacrifice the queen, after 4 moves White is up a bishop [W:B+] .. continuing the alternative line through move 11 using Fritz's best choices, White is up a bishop and a pawn [W:B+ P], yet the evaluation is now at (11.34)!

the position remains complex to me .. obviously, something is going on i don't see .. after move 11 in my alternative, Black is under heavy attack with the saved queen harmlessly isolated at h4 .. by move 13 Black has lost a rook, thus the increased evaluation count

sadly, for me (lucky for you), my version of "Fritz 6" with Chessbase Light doesn't allow me to save the work i've done evaluating these variations .. otherwise, i'd add it to a list of problems i could re-visit and attempt to better understand .. for now, this will have to do

i promise someday i'll get over it or just ride off into the sunset .. until then, thanks for putting up with me

BTW, what is the correct tag? any commentary would also be most appreciated, drahacik

thanks again

[drahacikfm]

The idea of this problem is not too complex.  You don't need 11-move variations from Fritz to understand it:

After 1.Bf3, the Black queen has only 2 squares it can go to:

1) If it goes Qc4, then Bd5 traps it.  Black loses queen for rook (Qxf1).
2) If it goes Qe7, then Nd5 attacks the queen and also discovers an attack by the Bg3 on the Nb8, which is unprotected.  Black loses a knight after he moves the queen.

And that's really all there is to the problem.  Black decides instead of the above two alternatives, to take two bishops for his queen with Nxg3 and Nxe4.  That's not really an important part of the problem.

So the tags could be TRAPPED PIECE, although I hesitate to do that because the queen can go to e7 instead of c4, and it's not trapped.  A tag could be DISCOVERED ATTACK because of the discovered attack on the Nb8, but that variation didn't actually get played.  So I would say those 2 tags, or no tags at all.

The important point to understand is that in many problems on Chess Tempo the real ideas are hidden in variations that were not played, because the computer bails out immediately by giving away material on the first move.  It's not worth analyzing and assigning tags based on the bail-out move or anything that comes after that, because it is not relevant to the problem.  Here, Nxg3 is the bail-out move and all tagging should stop there and no more deep analysis or thinking should be done after Nxg3.

[texian]

thanks for another excellent description to a confusing problem, drahacik .. my chess brain has been sputtering the past few days .. so, i hadn't responded and didn't want to forget .. you have a great way of describing solutions to problems that, for me, have been very hard to see .. thanks especially for that

i've decided to give up tagging problems, other than the most obvious untagged or erroneously tagged ones, until we get Richard's "offical" list of tag descriptions and hopefully some examples .. but thanks for your help with these .. i'm sure i'll have other questions later and you're the go to man

[dhingzpe]

i added my votes on all tags .. i keep forgetting to do that .. i have noticed that whenever i vote against a tag it is *always* removed from the problem .. i am assuming that means it had only one vote for it which seems surprising

Agreed. Most of the time, when I vote against a tag, it will be gone, but not all problems ave tags which are only +1.

[richard]

Yes, I think most people who see a problem is already tagged don't bother voting for the same tag again. Also tags that need voting against are mistakes which are hopefully less common than correct tags :-)

Regards,
Richard.

[qui]

There is a simple idea to encourage more people to "anchor" a tag (or to remove it): 2 small icons next to each already assigned tag, one meaning agreeing and one meaning disagreeing. This way a solver can quickly add another vote to a tag without having to use that tag list and without a possibility of a miss-click.

Another useful thing would be a description of each motif and difference between similar ones. Sometimes I come across an untagged problem and I wish to tag it, but I am often unsure which tag is a correct description of the problem, so I just leave it alone.

[richard]

i Qui, I like the agree/disagree idea.  I've had a tag descriptions page about 80% done for some time now, but getting the other 20% finished has proven an elusive goal at the moment :-/  It will probably be at least 6 weeks away.

Richard.

[dhingzpe]

I've had a tag descriptions page about 80% done for some time now, but getting the other 20% finished has proven an elusive goal at the moment :-/  It will probably be at least 6 weeks away.

That will be great! People will stop tagging for fun.

[revenant]

Oh is that what's happening?  I tried problem set search on a tag once or twice but the resulting serve-ups didn't seem to have the theme in question.   

On the other hand, there is probably a fair amount of unintentional mistagging as well so I don't wish to just blame other users -- I think I may have mistagged some problems as "blocking" because I don't really understand the tag (I thought of it as doing something like a capture & recapture to cause an opponent's piece to block or "clog up" a useful square, like "interference", but other people apparently see it as something different so I don't do that anymore).  (I will gladly atone for my sins if shown a list of them which I can go back and untag.)

I *do* still tag:  a) "hanging piece" because those make me mad and I want to do whatever I can to help others avoid missing them  , and b) "interference" since that seems relatively clear (place one of our pieces between two enemy pieces or an enemy piece and a square so they don't protect each other anymore) and it's a cool theme.

[richard]

Another thing I have fairly high on the todo list is to weight some user's tags differently to others (an idea discussed on the forum previously - not my idea, but I can't remember who to give credit to off the top of my head).  Some users regularly miss-tag problems, this is obvious by how many "against" votes their tags get (after normalising for total number of tags done for the user) and weighting their votes less than others should lead to a much better quality "search by tag".

Richard.

[qui]

Richard, if it's 80% complete, why don't you share these 80%? It surely would help in many cases. Also, someone might finish the rest. (but not me, I'm too tag-confused )

[richard]

If it was just adding the missing stuff I'd probably upload it now, but half of the 20% is fixing the stuff I've got wrong. I'd rather not expose everyone to the full brunt of my stupidity (as opposed to the [somewhat] filtered view everyone already receives :-)  ).

Richard.