Author: Ricardo Gibert
Date: 18:08:03 10/04/99
Go up one level in this thread
On October 04, 1999 at 18:22:29, Robert Hyatt wrote: >On October 04, 1999 at 13:54:55, Ricardo Gibert wrote: > >>On October 04, 1999 at 13:07:51, Robert Hyatt wrote: >> >>>On October 04, 1999 at 11:43:47, Ricardo Gibert wrote: >>> >>>> >>>>But what about the example of a drawing sac? Why leave that one out? >>>>Technically, mate (mate is really misnomer) is a "forced concession of the >>>>battle", you don't actually kill the king. That's why we have a complicated >>>>mating rule. It would be simpler to just capture the K, but the inventers wanted >>>>to keep the game "polite" and leave the really _fun_ part out. Perhaps, because >>>>the game was actually anticipated to be played by real kings, they decided it >>>>was "wiser" to leave the last grisly detail out. Killing a king is not really >>>>fun when a _real_ king can really kill you in return. But this not _my_ reason >>>>for calling it a sac. It is a sac when I give something up and I don't collect >>>>the material back, either because of mate or a forced draw or whatever (=your >>>>version?). Being "prevented" from getting the material back, because an opponent >>>>resigns or draw is agreed, does not count of course. >>>> >>> >>>I didn't leave the draw option out. It is _identical_ to the mate situation. >>>A program plays a move, and discovers that it can checkmate you no matter what >>>you can do. Is that a sac? >> >>It is if material was given up to do so. >> >> >> A program is behind (losing to you) and discovers >>>that if it makes a move it can force a repetition no matter what you can do. Is >>>that move a sac? >> >>It is if material was given up to do so. >> >> >>Or is it suddenly unimportant since it starts a forced >>>combination that ends the game forcefully, whether winning or drawing? >>> >>>That is the ambiguity I don't like in the general use of the word "sac". >>>"sacrifice" means to give up something. I am not giving up something if I >>>mate you in the process... I am getting back more than I gave up many times >>>over. >> >>Of course you are getting back. That's the point of the sac. Why sac if you >>don't get a net gain? >> >> >>Ditto for drawing if I am in a losing position... >>> >> >> >>What is given up is _material_. What you don't get back is the _material_. What >>you get back is something else. That's a sac to put it simply. When get nothing >>or too little back, it is not a sac, it is a blunder. >> >>> > > >that definitely isn't true. I have seen _many_ gm players make what they call >a positional sacrifice... they allow their pawns to get ripped for what they >hope is a compensating long-term weakness in the opponent's position that they >can exploit _first_. So you can sacrifice material or positional considerations, >and you can find combinations that win material or positional compensation for >your side... > >the term is _still_ way too fuzzy, IMHO. Because sacrifice means to give up >something you consider valuable. Not trade it for something even _more_ >valuable... IE the "ultimate sacrifice" where soldiers give up their lives >for no gain that they will ever realize... they do it for reasons that they >consider more important than living themselves... The issue is material, not what is more valuable. Sheding material is a sac. > > > >>> >>>> >>>>By my way of looking at things, a mating combination may or may not include a >>>>sac. I prefer to keep the distinction, rather than meld them together as you do. >>>>People enjoy the sac version of a combo more. Reason enough to keep the >>>>distinction IMHO. >>> >>>Doesn't bother me... if we agree that the definition of a 'sacrifice' is to >>>give up material at some point, whether you get it back or not... The only >>>problem with that definition is that in computer games (particularly those >>>against humans) it happens so often that it becomes a bland happening. I see >>>such 'sacrifices' (combinations) in most every game against a human played at >>>blitz time controls... >>> >>> >>>>Definitions are fairly arbitrary. I choose an objective >>>>definition that can be applied by anyone. You choose one that is subjective. >>>>Taking the Rebel game as an example. If a 1200 played that "sac" it would be a >>>>true sac, since he cannot reasonably be expected to calculate all the >>>>ramifications. If a GM plays the sac, maybe it is a sac or not, depending on the >>>>player, time situation, etc. A GM could calculate it to the point where he gets >>>>the material back or play it based on intuition. I don't care for this >>>>ambiguity. >>>> >>> >>> >>>Not a problem for me either way. If the word must stay totally ambiguous, >>>I can live with it... But a sac from a GM and a sac from a program are two >>>totally different concepts. Because a program will _never_ do it 'just because >>>it feels right' while a GM will do it regularly for that reason, without being >>>able to calculate all the repercussions... >> >>A program will do it as a gamble. You clipped an important part of my post that >>addressed this. What gives? > > >Programs do _not_ gamble. They search a finite tree. They choose the path >that leads to the best score within that tree. No way can that be considered >'gambling'... Huh? When you make decisions based on a incomplete information, it's gambling. Case closed. > >If you want to say that some evaluation terms are 'speculative' I would agree. >But even then the program isn't gambling at all. The programmer is by having >such a term...
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