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        Arimaa >> General Discussion >> Endgame Puzzle 2
        
(Message started by: jdb on Jul 27^th, 2008, 5:11pm)

Title: Endgame Puzzle 2
Post by jdb on Jul 27^th, 2008, 5:11pm

Not too tough, but proper technique required.

1w Ra1 Dg4
1b ce2 rf8
2w pass

Link to planning window:
http://arimaa.com/arimaa/games/planGame.cgi

edit: It is silver to move.

Title: Re: Endgame Puzzle 2
Post by omar on Jul 27^th, 2008, 8:33pm

If it is gold to move then just advancing the rabbit 4 steps is a win right?

Title: Re: Endgame Puzzle 2
Post by clauchau on Jul 28^th, 2008, 3:56am

Excellent. Gold also threatens to remove Silver's last rabbit. Combining those threats with the need for Silver to get closer to winning, I can see at least two winning moves for Silver. One seems faster than the other but I'm not sure.

Title: Re: Endgame Puzzle 2
Post by RonWeasley on Jul 28^th, 2008, 4:51am

I love these. Thanx! jdb. I found only one winning line for silver.

Title: Re: Endgame Puzzle 2
Post by omar on Jul 28^th, 2008, 10:09am

Thanks for the update JDB. I should have figured it was silvers move; otherwise it's too easy :-)

Title: Re: Endgame Puzzle 2
Post by clauchau on Jul 30^th, 2008, 3:57am

The following move doesn't look optimal but does look winning to me : 2b ce2w cd2w rf8w

Title: Re: Endgame Puzzle 2
Post by Fritzlein on Aug 5^th, 2008, 2:33pm

on 07/30/08 at 03:57:13, clauchau wrote:

The following move doesn't look optimal but does look winning to me : 2b ce2w cd2w rf8w

No, I don't think that works. After 3g Dg4n Dg5n Dg6n Dg7w, Silver's options are very constrained. Using one or two steps on the rabbit will allow Gold to set up a capture in one more move. Moving the rabbit three steps west and using the fourth step on the cat still allows Gold to freeze the rabbit with capture in two, while Silver will need three moves to capture the gold rabbit. Therefore 3s re8w rd8w rc8w rb8w seems forced.

Then 4g Ra1n Ra2n Ra3n Ra4n forces Silver to play the cat to either a4 or b5, which Gold answers with D->d5. Silver's rabbit is too badly placed to race, so the best hope seems putting the gold rabbit back to a3, with the silver cat on a2 or a4. If a2, then D->b3 seems to win. If a4, then D->b4 leaves Silver with only her rabbit mobile. The silver rabbit can't get too near the gold dog without risking an immobilization loss, so maybe r->e1 looks called for. But then 7g Db4e ca4e Dc4e cb4e brings the end near.

Endgames confuse me so much that I have surely overlooked something. Please point out the hole(s) in my analysis.

Title: Re: Endgame Puzzle 2
Post by jdb on Aug 5^th, 2008, 3:58pm

on 07/30/08 at 03:57:13, clauchau wrote:

The following move doesn't look optimal but does look winning to me : 2b ce2w cd2w rf8w

This move does not win, but it does take the most moves to lose. Fritz's move is the only defense to this move.

Title: Re: Endgame Puzzle 2
Post by clauchau on Aug 6^th, 2008, 3:55am

Wow, thanks Fritzlein and jdb. I agree now. That's tough and interesting.

Title: Re: Endgame Puzzle 2
Post by jdb on Aug 19^th, 2008, 12:41pm

THE SOLUTION IS BELOW

1w Ra1 Dg4
1b ce2 rf8
2w
2b rf8w ce2w cd2w cc2w
3w Dg4n Dg5n Dg6n Dg7w
3b re8w rd8w rc8w cb2s
4w Df7w De7s De6s De5s
4b rb8w cb1n ra8e cb2w
5w De4s
5b rb8s rb7e ca2n Ra1n
6w De3s De2w Dd2n Dd3n
6b rc7e rd7e re7e rf7e
7w Dd4e De4e Df4e
7b rg7s rg6e ca3e Ra2n
8w Dg4w Df4w De4s De3w
8b rh6s
9w Dd3s
9b rh5s rh4s rh3s rh2s