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        Arimaa >> General Discussion >> Endgame Puzzle 3
        
(Message started by: jdb on Mar 31st, 2011, 8:43am)
Title: Endgame Puzzle 3
Post by jdb on Mar 31st, 2011, 8:43am
Silver to play and win

1w Rc2 Dh7
1b cg6 rc8
2w pass

http://arimaa.com/arimaa/games/planGame.cgi

I will add it to the puzzle collection later.
http://arimaa.com/arimaa/puzzles/show.cgi?p=p61
Title: Re: Endgame Puzzle 3
Post by Fritzlein on Mar 31st, 2011, 9:49am
I love this puzzle already.  My first impression was that there was more than one way for Silver to win, but after working out a few lines, it suddenly feels like nothing wins.  What's the over/under on my solution time?  :)
Title: Re: Endgame Puzzle 3
Post by chessandgo on Mar 31st, 2011, 12:56pm
I can't see anything either. Gold being able to play R->a4 on the next move crushes most of the moves I can come up with.
Title: Re: Endgame Puzzle 3
Post by jdb on Mar 31st, 2011, 4:10pm
I double checked in case there was a typo.

The puzzle is correct.
Title: Re: Endgame Puzzle 3
Post by Hippo on Mar 31st, 2011, 6:04pm

on 03/31/11 at 12:56:15, chessandgo wrote:
I can't see anything either. Gold being able to play R->a4 on the next move crushes most of the moves I can come up with.

Ra4 is not good answer to cd5 or ce4 what were my first intuition after realizing non cat move leads to goal in 2 by 4/5 opposition. 1 cat step loses to Ra4 and goal/cat freeze next turn. So at least 2 cat steps are required ...
Title: Re: Endgame Puzzle 3
Post by rbarreira on Mar 31st, 2011, 6:16pm
When I analysed this with briareus, performance varied between runs but it still looks like this is the hardest puzzle so far...
Title: Re: Endgame Puzzle 3
Post by aaaa on Mar 31st, 2011, 9:13pm
Maybe it involves a repetition fight.
Title: Re: Endgame Puzzle 3
Post by Hippo on Apr 1st, 2011, 11:27am
Fortunately I have appropriate parity for my post :)
It seems to me position cc5 ra7 Ra4 Dh7 after 2 first turns is forced, but the first turn has two options ... with ra7 or rb7 and cg5 or cf5. Than D*, Ra3 ca4, Dc4, Ra1 ca2, and r starts it's way to h5 so finally R is captured in C3. :)

Oh no, cb5 rb7 is better as gold would play Ra6 Df7 otherwise. So the solution rb7 cf5 seems to be unique.
Title: Re: Endgame Puzzle 3
Post by chessandgo on Apr 1st, 2011, 12:59pm
Awwwww nice, thanks for the tip jdb.

EDIT: lol, now I understand the parity thing ^^
Title: Re: Endgame Puzzle 3
Post by chessandgo on Apr 1st, 2011, 1:00pm
Spoiler: solution attempt:

Come'on mate, you gotta warn us that the rabbit is supposed to win on the freaking furthest goal square :) Well, actually, I wondered whether that was the most elaborate April's fool joke in the history of ever, giving a hard puzzle the day before, planning to follow-up with a seemingly easy tip which actually doesn't work due to a cunning defense so that people think they got the solution... But well, if that's the case I'll be happy to be (one of) the fool(s) :)

2s rc8ws cg6sw
3g Rc2wwnn
3s cf5wwww
4g Dh7wwws
4s cb5w Ra4s ca5s
5g De6ssww
5s rb7eees
6g Dc4we ca4e Ra3n
6s re6seee

I love how the weak-piece side wins in your clue puzzle. I had that position on the board and thought it was won for the strong piece-side. But no, we win because our piece faces the enemy rabbit on the edge of the board, which is a standard good-defense pattern. Lately, it seems that half the time I look at a position I assess it improperly, but every time someone shows me why, I go "hey, but that's in my book!"
Title: Re: Endgame Puzzle 3
Post by Hippo on Apr 1st, 2011, 3:04pm
OK definitely I agree, pushing the Rabbit to a1 is losing move, rabbit should start it's run to h5 as fast as possible.
Title: Re: Endgame Puzzle 3
Post by Adanac on Apr 2nd, 2011, 10:02am

on 03/31/11 at 08:43:25, jdb wrote:
Silver to play and win

1w Rc2 Dh7
1b cg6 rc8
2w pass

http://arimaa.com/arimaa/games/planGame.cgi

I will add it to the puzzle collection later.
http://arimaa.com/arimaa/puzzles/show.cgi?p=p61


Another great endgame puzzle :) The move 2g pass is missing from the puzzle when I click on this link though.
Title: Re: Endgame Puzzle 3
Post by jdb on Apr 2nd, 2011, 10:54am

on 04/02/11 at 10:02:03, Adanac wrote:
Another great endgame puzzle :) The move 2g pass is missing from the puzzle when I click on this link though.


Hmmm, anyone know how to modify a puzzle?
Title: Re: Endgame Puzzle 3
Post by Fritzlein on Apr 2nd, 2011, 2:02pm

on 04/02/11 at 10:54:09, jdb wrote:
Hmmm, anyone know how to modify a puzzle?

I'm pretty sure you can't modify it; you have to re-enter it from scratch and delete the first attempt. :-/
Title: Re: Endgame Puzzle 3
Post by Fritzlein on Apr 2nd, 2011, 9:34pm
OK, finally got it with the help of the solution to Puzzle 4.  Like chessandgo, I reached the Puzzle 4 position in analysis and mis-evaluated it.  Then I tried to solve Puzzle 4 as a crutch, and came up with a bogus solution!  There is way more going on in these miniatures than one might imagine.  Thanks again, jdb, for providing us with such entertaining instruction.
Title: Re: Endgame Puzzle 3
Post by omar on Apr 5th, 2011, 6:15pm
I fixed the puzzle; no need to resubmit it.

Wow, this one was really hard. I couldn't get it.


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