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        Arimaa >> Game Analysis >> Game 147053 (183629) - Korhil vs starjots
        
(Message started by: Korhil on Jun 20^th, 2010, 9:15pm)

Title: Game 147053 (183629) - Korhil vs starjots
Post by Korhil on Jun 20^th, 2010, 9:15pm

In the game, 23g is definately an error, but with the 23s played, the position reaches the point I was happy to play into.

In the next series of moves material is taken off. After 27g Gold has material compensation of a Dog & 3 Rabbits for his caMel.

I was happy to play to that position, and I still think it looks fine for Gold, but I didn't think Gold was really winning until after 35s when Gold won a Horse for a Cat.

Is the position after 27g still in the balance, or is it more one-sided than I thought. Gold's a5 Rabbit is weak.

Cheers,
Martin

Edit: Typos

Title: Re: Game 147053 (183629) - Korhil vs starjotscomp
Post by Fritzlein on Jun 20^th, 2010, 11:07pm

http://arimaa.com/arimaa/gameroom/comments.cgi?gid=147053

With one pair of horses off, I prefer DRRR to M, but if that had been the only trade, I would prefer M to DRRR. It is close either way.

Silver is more likely to be able to win something for nothing, because the silver elephant and silver camel each can make a threat. Only the gold elephant is strong enough to defend either threat, so it must choose one and accept a loss on the other side.

On the other hand, with three pieces fewer, it would be catastrophic for Silver to give up the camel as a hostage, which constrains the camel's effectiveness. Usually the damage of giving up a camel hostage can be mitigated by a swarm, if not turned into outright advantage by a swarm. In this case, however, so many silver pieces are already off the board that swarming is unlikely to be viable.

I would say the position after 27g is still very much in balance. Between bots or beginners, having more pieces is worth more than having the deputy. As the players get stronger, however, the value of the camel goes up, because the player with the camel knows what kind of control game the position mandates, and the player without the camel doesn't have the firepower to gain control or contest it properly.

Immediate tactics aside, Silver's dream position with that material imbalance is to get an elephant-horse attack going. It would be difficult for Gold to defend against an EH attack with anything less than his own elephant, but if his elephant gets tied down to defense, then the silver camel becomes sheriff of the rest of the board. I love being on the right side of that kind of control position, when I have a free piece the other player can't match. From then on it's shooting fish in a barrel as the free camel picks off little pieces one by one.

But when the players don't understand the control issues, it is likely that there will be some kind of race or trading going on. Every trade, even an "equal trade", weakens Silver's position and makes Gold's numerical superiority count for more.

Title: Re: Game 147053 (183629) - Korhil vs starjotscomp
Post by Korhil on Jun 21^st, 2010, 2:31am

on 06/20/10 at 23:07:12, Fritzlein wrote:

I would say the position after 27g is still very much in balance. Between bots or beginners, having more pieces is worth more than having the deputy. As the players get stronger, however, the value of the camel goes up, because the player with the camel knows what kind of control game the position mandates, and the player without the camel doesn't have the firepower to gain control or contest it properly.

Do you know of an example game that shows the bigger piece being used correctly to stop many smaller pieces?

http://arimaa.com/arimaa/gameroom/comments.cgi?gid=146878
Is another game I recently finished from the Postal Mixer where I also played to get lots of small pieces for my Camel.

Cheers,
Martin

Title: Re: Game 147053 (183629) - Korhil vs starjotscomp
Post by Fritzlein on Jun 21^st, 2010, 10:20am

I can't recall any recent times where I won a camel for little pieces; somehow that used to happen more often. Have you read my commentated game against Omar from the 2005 Postal Championship?

http://arimaa.com/arimaa/twiki/bin/view/Arimaa/FritzleinVsOmar2005PostalChampionship

It's a bit dated, but I think it still gets the point across that the side with the camel can make two material threats more easily than the side without, whereas the side with more numerous pieces has an easier time generating a race.

Title: Re: Game 147053 (183629) - Korhil vs starjots
Post by Korhil on Jun 21^st, 2010, 2:57pm

Thank you, that is helpful.
The material difference isn't as great however. With one player 3 Rabbits down, it becomes much harder for them for create their own goal threats and they are more forced to play a control game.
In that game, you are able to advance your Rabbits to stretch the defences of the weaker side.

Title: Re: Game 147053 (183629) - Korhil vs starjots
Post by Fritzlein on Jun 21^st, 2010, 3:26pm

Yes, your exact material imbalance is unusual. I don't recall ever seeing it before. That is a reason you should take anything I say about it with a grain of salt.

Title: Re: Game 147053 (183629) - Korhil vs starjots
Post by Korhil on Jun 21^st, 2010, 7:36pm

Would it be possible to conclude that some number of Rabbits in exchange for a Camel makes the task too hard for the Camel?
I've had 4 pieces for the Camel in each of the games I've mentioned - 3 Rabbits plus either a Cat or Dog.
Perhaps 4 Rabbits alone is also too great for a Camel to contain. Or simply, a Camel can't control 4 pieces (the difference in the numerical strength of the forces).

In your game with Omar, I don't think that Horse + Cat is equal to a Camel. I would rather have the Camel given those options.

What I'm really asking is; should I continue to give up my Camel for a pile of Rabbits, and if so, how many will I need to have sufficient compensation vs a top level player.

Cheers,
Martin

Title: Re: Game 147053 (183629) - Korhil vs starjots
Post by Fritzlein on Jun 21^st, 2010, 8:32pm

on 06/21/10 at 19:36:28, Korhil wrote:

What I'm really asking is; should I continue to give up my Camel for a pile of Rabbits, and if so, how many will I need to have sufficient compensation vs a top level player.

And what I'm really saying is that I don't know. That material imbalance never happens as the first trade. Even three rabbits for a horse is very rare. I can give you my opinion that a camel is clearly worth more than four rabbits as the opening trade (remember that at that point the camel still has lots of help guarding the goal), but I have never put my theory to the test. You may know more about it than I do, so don't stop doing whatever is working for you.