Welcome, Guest. Please Login or Register.
Jun 6th, 2020, 6:16am

Home Home Help Help Search Search Members Members Login Login Register Register
Arimaa Forum « 2015 Move 12g »

   Arimaa Forum
   Team Games
   2009 One vs TheMob
(Moderators: supersamu, RonWeasley)
   2015 Move 12g
« Previous topic | Next topic »
Pages: 1 2 3  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print
   Author  Topic: 2015 Move 12g  (Read 3649 times)
Forum Senior Member

Arimaa player #9500


Gender: male
Posts: 28
Re: 2015 Move 12g
« Reply #30 on: Dec 24th, 2015, 10:23am »
Quote Quote Modify Modify

on Dec 23rd, 2015, 1:56pm, aaaa wrote:

I don't see why Gold can't play the more obvious 13g Mb3w Ma3e ha4s xxxx here, after which the given 13s looks like a bad idea, as instead of recapturing immediately, Gold could frame the horse first (with a goal threat).

Upon further consideration, this might be a good option. It's a rabbit sacrifice in exchange for a camel hostage.
12g. Mb5s hb6s Mb4s hb5s  
12s. mc6w mb6s Ha6e hb4w  
13g. Mb3e ha4s Ma3w Dd2n  
13s. rh6s rh5s Rg5w hg4n  
14g. Ef4w Ee4w Ed4w Ec4n  
14s. df6w Rf5n Rf6x Dd3w ee3w
15g. mb5s Ec5w mb4w Eb5s
Next, if 15s. ed3n ed4w ec4n ec5w then 16g. Cc2 Dc3s Rb1w Rg2e. In the end, the likely outcome is that a pair of horses gets traded, we lose the a5 rabbit but silver also loses a rabbit on h4, and silver camel gets stuck in the west while ours has free reign in the east. If this is correct, then this is good for us.
« Last Edit: Dec 24th, 2015, 12:39pm by Lion » IP Logged
Forum Senior Member

Arimaa player #9500


Gender: male
Posts: 28
Re: 2015 Move 12g
« Reply #31 on: Dec 24th, 2015, 10:49am »
Quote Quote Modify Modify

on Dec 23rd, 2015, 6:56pm, half_integer wrote:
After 1a.1 I think we also need to beware of  
  13s Rb5w mb6s hb7s rc7w

Yeah, this is pretty good. It lets silver get his horse in the game immediately. However, this does not necessarily mean this is a bad position for us. If the silver horse goes after our rabbits in the east (to prevent elephant rotation), then we are likely to get control over the c6 trap, freeing our camel. On the other hand, the silver horse cannot easily penetrate through the center to attack c3, so perhaps it has to stay put in the center. If this is the case then maybe we'll have time to rotate the elephant. Therefore, I am comfortable choosing the horse frame for 12g.
Having said that, maybe the horse pull could turn out to be a better option, after all, as I noted in the post above. Gotta calculate some more ... Smiley
« Last Edit: Dec 24th, 2015, 10:50am by Lion » IP Logged
Forum Guru

Arimaa player #8819


Gender: male
Posts: 104
Re: 2015 Move 12g
« Reply #32 on: Dec 24th, 2015, 3:06pm »
Quote Quote Modify Modify

I also am not so sure that the frame is the best move anymore.  The double pull to b3 seems to work out OK, and the Ec5 also seems to threaten the camel enough to avoid silver attacking the f3 trap.  I'm not sure whether the tactics actually lead to a capture though.  Still, it moves the fight into silver's half of the board instead of around f3.
The frame seems to lead to silver setting up a camel capture for horse loss - however I think we can set up an additional capture or positional advantage which might still leave us ahead.  I recall that I think sharp is weaker at playing after asymmetric trades too.
Time to make an expanded tree I think.
IP Logged
Forum Guru

Arimaa player #8819


Gender: male
Posts: 104
Re: 2015 Move 12g
« Reply #33 on: Dec 26th, 2015, 8:42am »
Quote Quote Modify Modify

OK, the move (horse frame) has been made.  In our discussion, we only identified one silver reply to this move (12s Cd7 Rc7 Hb7 Mb6) so I think we can work on the next Gold reply.
The only piece that can protect the a6 horse is our camel, put on c5 or d6.  d6 doesn't appear desirable as it quickly leads to camel loss or various frames.  Mc5 alone is not good as it allows silver Mb5 Ed5 in one move which leads to immediate camel loss (Hb6 is false protection and the silver camel pull cannot be blocked).  To prevent that 13s I see two measures: pull the d6 dog with Mc5:Dd5 which allows Ed6 in 4 steps, or put a piece on b5, where Ra5b5 is the only one that can reach.  This latter move leaves us two free steps which we can debate below.
The wild-card move would be to not defend the horse and play for a rapid elephant rotation, with Mf5 or Me4.  There may be some moves with the same goal which do not use all four steps for the camel this move (though Me5 is not one of them: Dd5 E:Me6 is immediate camel-for-horse trade).
It is important to note that the camel-for-horse trade may be inevitable, at least in the lines where we defend c6, so rather than always reject lines with camel loss for horse sacrifice, we should determine if we can protect the a6 horse or get greater compensation.  Conversely, if we cannot protect the a6 horse long term then making progress now by not defending it becomes attractive.
So, an updated tree (SM notation only to save typing):
12g ::Hf3
12s Cd7 Rc7 Hb7 Mb6
    1 Md6:Dc6
    - 1.1 Dc5 Ed5 (Hf3x) - indefensible camel loss with horse hostage
    2 Md6:De6
    - 2.1 Ed5 (Hf3x) Mb5
    - - 2.1.1 Ec5
    - - - De7 Cg7 Df7 Hb6 - f6 cannot be defended but maybe a camel trade can be threatened?
    - - - - E::Mb3
    - - - - - Ec4::M
    - - - - - - (E/R) Md5 Dd3 - and we seem to have freed our camel and gotten a camel hostage after two more moves?
    - - - - E:Mb4 (Dd3 Hg4)
    - - - - - Ec4::M - and our camel seems to have escaped
    - - - - - Ec4 Ma4 X - our camel escapes here too
    - 2.2 Ed5 (Hf3x) X  
    - - 2.2.1 Dc5
    - - - E:Mc6 X X - camel loss is unavoidable
    - - 2.2.2 Ec5
    - - - E:Mc6 X X - this frame looks like an easy elephant rotation for silver, though we are up a horse in the short term
    - - - De7 Cg7 Df7 X - f6 cannot be defended, but this time it is harder to make camel threats in response
    3 Mc5 X X X
    - 3.1 Ed5 (Hf3x) Mb5 - camel is indefensible and we still have a horse hostaged
    4 Mc5:Dd5 - note I didn't find any really bad responses to this yet
    - 4.1 Ed4 (Hf3x) Dd6 Ed5
    - - 4.1.1 Ec4 Mb5 - doesn't appear profitable for silver, he gets a horse trade at best
    - 4.2 Ed4 (Hf3x) De5 Ed5
    - - 4.2.1 Ec4 Mb5 - still just a horse trade for silver
    - 4.3 Ec4 (Hf3x) Mb5
    - - 4.3.1 Ed6
    - - - E:Mc6 Mb6 X - this frame looks difficult but not impossible to rotate, so this position might be OK for gold (up a horse for a camel frame)
    - - - E:Mc6 Hb6 Ra7b7
    - - - - Ha7 M:Ha6 X - a strange little position which might leave the silver camel as strongest free piece but also gives gold access to the back ranks in the west
    - - - is there an even better silver move?
    - 4.4 Ec4 (Hf3x) Cd6
    - - 4.4.1 Rb5 M:De5 X - silver seems to get the horse and rabbit at c6 but it looks like gold's camel can always escape
This has taken a while so I'm going to edit in more later.
    5 Mc5 Rb5 X X - to be expanded
    6 Mf5 / Me4 / Md4 X / Md5 X X / Mc4 X X - lots of work to do here
I noticed that I'm almost exclusively focused on the silver moves which sacrifice the framed horse; there is the possibility of silver responses which defend but don't try for a trade.
« Last Edit: Dec 26th, 2015, 11:56am by half_integer » IP Logged
Pages: 1 2 3  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print

« Previous topic | Next topic »

Arimaa Forum » Powered by YaBB 1 Gold - SP 1.3.1!
YaBB © 2000-2003. All Rights Reserved.