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Title: Positional Features vs Material Post by jdb on Jun 1st, 2006, 6:00pm What positional features do you think are worth more than a rabbit? In other words, what positional feature would you be willing to give up material in order to get? And how much material? 1) Elephant blockade 2) Camel hostage Any others? |
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Title: Re: Positional Features vs Material Post by 99of9 on Jun 1st, 2006, 6:29pm 3) a horse frame where my elephant is not required to defend |
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Title: Re: Positional Features vs Material Post by Ryan_Cable on Jun 1st, 2006, 8:49pm 4) Goal threat 5) Total control of enemy trap 6) Shared control of both enemy traps 7) Advanced R with potential to threaten goal (sometimes) 8) H hostage held by M (sometimes) |
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Title: Re: Positional Features vs Material Post by Fritzlein on Jun 1st, 2006, 9:58pm I've played in several games recently where one side gets a rabbit capture in the opening while the other side sets up a camel holding a horse hostage. The is a huge variety in how much the camel holding the horse hostage is worth, but it seems to be worth more than a rabbit more often than it is worth less. It's fairly rare to get a dog hostage, but a horse holding a buried dog hostage is probably worth more than a rabbit as well, most of the time. A cat hostage in the opening very often turns out to be a lost cat, in my experience, so a cat hostage could be considered worth more than a rabbit capture, although it isn't a strategic feature of the position which is likely to persist for very long. I agree with 99of9 that a horse frame where the elephant doesn't have to participate in the frame is worth more than a rabbit. That leaves open the question of the value of a horse frame where the elephant is holding in the horse. Some of those are worth more than a rabbit too, in large measure because the elephant can be relieved of its post eventually. It requires some judgment to guess whether the elephant can eventually rotate out of the frame, and if so, how much damage will happen in the mean time. The value of a goal threat deserves the "sometimes" tag even more than the hostage situations do, because lots of times a rabbit threatening goal is merely a doomed rabbit. Tactically the goal threat is only worth something if I also have a second threat which can't be blocked because the goal threat has to be blocked first. To be considered a strategic advantage offsetting a material disadvantage, the rabbit has to be safe from immediate capture. It could be on a7 or h7, say, or else the player could have shared control of the nearest trap. |
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Title: Re: Positional Features vs Material Post by chessandgo on Jun 2nd, 2006, 12:50pm all this is interesting, and what about "bigger" sacrifices ... the only player I've ever heard mention that he would do a piece sacrificing move completely willingly was PMertens (in the comments of a recent game between him and Fritzl). Are there examples of games involving some kind of long term and completely stratgic compensation (as opposed to tactical ones such as goal threat or upcoming material win ...) ??? |
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Title: Re: Positional Features vs Material Post by RonWeasley on Jun 2nd, 2006, 1:55pm The "bait and tackle" comes to mind. This is where you sacrifice the cat behind your trap in the opening to blockade the opponent's elephant. |
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Title: Re: Positional Features vs Material Post by chessandgo on Jun 2nd, 2006, 2:39pm yeah, but appart from bait and tackle and other "identified" features as listed by jdb and the others ... ? I'm particularly asking this because at chess sacrifices are quite usual, often relying on unclear advantages such as piece activity ... and even in recent times and in opening theory positional sacrifices which seem very unplausible have known an incredible rise ... |
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Title: Re: Positional Features vs Material Post by chessandgo on Jun 2nd, 2006, 4:12pm I don't know if I've made my question clear ; for instance, in game 32175 (which is interesting for many others reasons BTW !), after an alternative move for 20w proposed by Ryan, Paul says he would have sacrificed a cat, and doesn't care to lose it ... even if there seem to be no immediate compensation ... (and he's probably right ...) Are there other examples, either in actual games or in post mortem analysis of such sacrifices ??? |
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Title: Re: Positional Features vs Material Post by 99of9 on Jun 2nd, 2006, 4:58pm Adanac sacrificed his camel against me in last year's postal comp and won about 10 moves later. |
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Title: Re: Positional Features vs Material Post by PMertens on Jun 2nd, 2006, 5:40pm on 06/02/06 at 16:12:08, chessandgo wrote:
Always keep in mind, that I say a lot of things on a 24h day and that I prefer the interesting over the save solution ... That said my strategy certainly is not always sound ... but fun oriented :-P I really do have a hard time to formulate the way I play arimaa and the way I feel a position (as you might have found out by now I am not a big thinker, but a fast mover) Sometimes things just seem to be right ... or at least I cannot see whats wrong with it and it could get interesting ... No big help to your question, is it ? |
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Title: Re: Positional Features vs Material Post by PMertens on Jun 2nd, 2006, 5:43pm by the way ... did you not sacrifice a rabbit and a cat against me recently ? And you said it was worth it (while I said: I do not care for that pinned horse and the targeted camel) To bad I blundered a few moves later, so I could not prove how wrong you were ;-) |
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Title: Re: Positional Features vs Material Post by aaaa on Jun 2nd, 2006, 6:38pm I assume this all refers to an initial rabbit? Slightly off-topic: Since the value of a rabbit heavily depends on how much of them there are, I think it would be better visualizing values when systems like FAME instead take an (initial) cat as an unit. After all, in chess, pawns don't generally become relatively more important, the less of them there are, as is best demonstrated in this legendary handicap chess game (http://www.chessgames.com/perl/chessgame?gid=1265302). |
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Title: Re: Positional Features vs Material Post by PMertens on Jun 3rd, 2006, 4:39am Quote:
and heavily on how much other pieces are there (own - defensive / opponent - agressive) ... therefore it obviously depends very much on the position, because a rabbit unneeded in defense and without possibilities to advance is for the moment rather worthless ... I believe it was not necessarily the initial rabbit that was meant ... |
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Title: Re: Positional Features vs Material Post by Fritzlein on Jun 3rd, 2006, 8:48am That's an amusing chess game aaaa, thanks for the link. FAME has a tendency to think big as the board empties out. That is to say, every capture towards the end of the game has a larger impact on the FAME score than towards the beginning of the game. I considered this a bug at first, but now I realize it is a feature: being ahead by X material late puts you closer to winning than being ahead by X material early when there is still time for your opponent to recover. Some of the positional features we're talking about here (blockade, frame, hostage) because less valuable relative to a rabbit later in the game, but strategic goal threats increase in value substantially, as does trap control in some cases. |
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