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        Team Games >> 2009 One vs TheMob >> 2015 move 14
        
(Message started by: clyring on Jan 16th, 2016, 7:42pm)
Title: 2015 move 14
Post by clyring on Jan 16th, 2016, 7:42pm
http://arimaa.com/arimaa/notconv/old/boardimg.php?orient=n&size=300&imgtype=png&ranks=r2rr/rhrc1r/Hm1d1crr/1RM2d1R/5E/4ehH/R1CDDCR/1RR2R1R
13s df6s rc8e cf7s rf8s has been played.
Title: Re: 2015 move 14
Post by half_integer on Jan 17th, 2016, 9:09am
Well, lightsharp did not take any of the moves we were expecting.  My reaction is that it probably assesses the situation in the west to be stable so it went ahead and advanced pieces for anticipated f3 control if our elephant leaves first.  The silver M:Ra5 threat still exists and now silver has more strength for f3 control.

If we assume the strategic situation is unchanged and that silver has quietly moved pieces into position, can we do the same?  One thought is that if silver is moving slowly, we could work on rotation at f3 - bring pieces east along the back ranks to eventually free the horse and then elephant.

Another thought is that is we can phalanx the silver camel then it cannot push to b5.  We currently need 6 steps to complete the phalanx, so taking two or more steps towards it now would allow completion next turn.  However, this might force silver's hand and we might see silver Mb5 as the 14s response.

So, Ra3 Rb2 Rce1 is one move that combines these ideas.  Rbb3 Rce1 is an alternate.  Consideration of silver responses might change the preferred move.  Raa5 Rb2 could allow Hb6 Ra6 after silver Mb5, setting up crossing through the trap on 16g.

One other idea to check: is there any chance that f6 is congested enough to make Md6:De6 X safe-ish, with an eye towards swarming c6?
Title: Re: 2015 move 14
Post by aaaa on Jan 17th, 2016, 9:41am
I don't have any concrete plan for Gold to pursue in this position, but one move that comes to mind is 14g Dd2n Cc2e Dd3n Dd4n, which would deny Silver the immediate opportunity of putting a dog of his own there and should mitigate the threat to the camel. Of course, one should never underestimate the tactical liability of abandoning a trap.
Title: Re: 2015 move 14
Post by mattj256 on Jan 17th, 2016, 11:07am
My immediate thought is to flip the silver dog to g4.

My other thought is to play Hg6 : Rg7.

My strategic thoughts: this is our last chance to let the elephant leave the f3 trap without immediate consequences.  I wanted to leave the frame last move (which didn't happen).  My feeling is if we're committed to the frame we should have a plan for rotating out the E, and otherwise we should get the heck out of there.

I'm a weak player and I don't have time now to examine moves in depth so, yeah, grain of salt..
Title: 15sRe: 2015 move 14
Post by Hufflepup on Jan 18th, 2016, 2:24am

Quote:
The silver M:Ra5 threat still exists and now silver has more strength for f3 control.


Is this really a good threat? It would mean abandoning the horse hostage, and the threat of bringing the elephant across next turn ccould be dealt with bby retreating the camel.


Quote:
If we assume the strategic situation is unchanged and that silver has quietly moved pieces into position, can we do the same?  One thought is that if silver is moving slowly, we could work on rotation at f3 - bring pieces east along the back ranks to eventually free the horse and then elephant.


I would be surprised if we had time for this. It would be difficult to stop a phalanx on the flanks being broken by silvers small pieces unless we kept the elephant over there, furthermore it would reduce goal defence in the west which could be an issue if silver suddenly abandons the trap with the elephant and heads east.


Quote:
One other idea to check: is there any chance that f6 is congested enough to make Md6:De6 X safe-ish, with an eye towards swarming c6?


This would allow silver to frame the camel on 15s, but some kind of rotation like this might be possible in the longer term.


Quote:
I don't have any concrete plan for Gold to pursue in this position, but one move that comes to mind is 14g Dd2n Cc2e Dd3n Dd4n, which would deny Silver the immediate opportunity of putting a dog of his own there and should mitigate the threat to the camel. Of course, one should never underestimate the tactical liability of abandoning a trap.


If we put our dog on d5 it would make witdrawing the camel more difficult if the silver elephant switches wings next turn. Ideally I would like to place the dog so it could threaten to come to c5 as part of a camel rotation which is a bit awkward from this position.


Another possibility to consider is:
14g: Ra2n Ra3n Ra4n Dd3n

If silvers elephant comes across it would allow us to sacrifice the b5 rabbit which is the only way we might be able to save the hostaged horse in this case.
Title: Re: 2015 move 14
Post by half_integer on Jan 18th, 2016, 1:15pm
I'm not in favor of aaaa's move since our camel still cannot be saved after
  14g Dd3 Cd2 Dd5
  14s M:Ra5 X X
now with silver Ec4 on 15s the camel cannot be saved.  The camel could be withdrawn on 15g, but then the horse can be pulled to b6.  The d5 dog plays no role, unless it could occupy c5 with the horse on b6, but that doesn't seem likely to work long term.

I'm more inclined towards Hufflepup's Ra5 Dd3 but I still think my Ra5 Rb2 is better, since after silver Mb5 we can end with Hb6 Ra6 from which I don't think silver can immediately threaten us; the horse flip probably requires the most analysis from there.  Other silver moves allow us to go through the trap from this position.  If silver plays Mb5 Hb6 Rb7 then it is awkward for him to threaten the horse after the camel withdraws; I think it takes three moves.

I considered both of matt's moves as well.  I don't know how to evaluate the dog flip because I don't know if we want it at g4 or not.  Maybe we even want it at e4?  Done carefully perhaps we could get the dog for a rabbit sacrifice at c6 and then return with the camel?  I can't evaluate that - however if silver doesn't want the dog at e4 it is only two steps to return to f5, so we've lost steps, and that observation probably invalidates that line (at least it does in my bot :) ).  As for the attack at g6 I doubt it will do anything; a simple Rh7 Rg7 Cf7 prevents progress.

Though I understand matt's argument about the frame, I feel we need to actually see a benefit from leaving; it is not enough to leave just because a deadlock means no progress.  So if someone finds a line that gives us advantage I'm all for it.

I tend to agree with Hufflepup that moving east for horse rotation is not likely a good idea; I just wanted to bring it up for discussion.

Regarding Md6 though, I don't think I agree with his assessment.  To frame the camel he would have to sacrifice the f3 horse, and the frame would be tying up his camel and elephant leaving our eastern horse as strongest free piece in the short term.  As well, he'd be invalidating his own hostage threat.  In the end, I don't think it is worth silver abandoning the frame unless he can win the camel outright, or at least the horse in trade plus something else.

So the end result for me is that there are two moves I consider prime candidates:
  Ra5 Rb2
  Md6:.De6 (Dd3 or Rb2)
Title: Re: 2015 move 14
Post by Hufflepup on Jan 19th, 2016, 2:46am

Quote:
I'm more inclined towards Hufflepup's Ra5 Dd3 but I still think my Ra5 Rb2 is better


The problem with both of these moves is that I don't think they would be enough to protect the horse if the elephant switched wings. e.g:
14g: Ra2n Ra3n Ra4n  Rb2/Dd3n
14s: dd6s cd7s re8s ce7s

Then we need to be able to handle something like 15s: ee3n ee4w ed4w df5e. Unfortunately it looks as if silver can just congest the centre too much  to get our elephant across in time to save the horse, and once the horse is captured an extra advanced rabbit is proably an additional liability, and goal defence in the east will be significantly weakened.

Maybe it would be better to fight for control of the centre with 14g: Dd2n Cc2n Rc1n Dd3n?

If silver abandons the frame on 14s it will need to spend all 4 steps with the elephant if it wants to move to c4 allowing us to threaten the f5 dog, probably leading to a dog fro rabbit excchange  in our favour. If the silver elephant moved to d5 I think we only lose a rabbit.If silver doesn't abandon the frame we are in a better position for a fight for the control of the centre than with a move on the flanks.



Quote:
Regarding Md6 though, I don't think I agree with his assessment.  To frame the camel he would have to sacrifice the f3 horse, and the frame would be tying up his camel and elephant leaving our eastern horse as strongest free piece in the short term.  As well, he'd be invalidating his own hostage threat.  In the end, I don't think it is worth silver abandoning the frame unless he can win the camel outright, or at least the horse in trade plus something else.


I agree with your assesment of the frame threat. A more serious concern is that the camel could be forked. 14s: ee3n ee4n ee5w de6n - our army is not sufficiently advanced to defend everything.
Title: Re: 2015 move 14
Post by half_integer on Jan 19th, 2016, 8:42pm

on 01/19/16 at 02:46:12, Hufflepup wrote:
I agree with your assesment of the frame threat. A more serious concern is that the camel could be forked. 14s: ee3n ee4n ee5w de6n - our army is not sufficiently advanced to defend everything.

I think you are right.  The camel cannot be forked immediately as f6 is blocked, but we would effectively have two hostages to defend after a few turns.  The only way to save it I think is if we can pull the silver camel after we come to c5 and threaten a camel exchange (being up the horse already).


on 01/19/16 at 02:46:12, Hufflepup wrote:
The problem with both of these moves is that I don't think they would be enough to protect the horse if the elephant switched wings.

I disagree about the fight at c6.  I don't see silver sacrificing the horse without first playing Mb5 to make the capture of our camel inevitable.  Otherwise we can still withdraw the camel in some way resulting in a horse trade, and we get two moves to threaten new pieces while he cashes in the horse and then rabbit.  I also see a lot of potential to diamond-cover the c6 trap with silver pieces to delay capture of the horse or rabbit since silver would have no place to end with the camel.

I was briefly liking the dog flip since it leaves it frozen where we could cash it in if the silver elephant leaves, but first, I don't think we'd have time anyway, instead leaving to defend the horse, and second, it is too easily removed by a simple g6 rabbit advance, and I don't like it on h3 or pushing our h rabbit to capture.

This leaves me still thinking that Ra5 Rb2 is the best move.  If silver does not choose Mb5 next move then we can complete the phanlanx and the camel threat is almost negated as far as I can see.
Title: Re: 2015 move 14
Post by mattj256 on Jan 19th, 2016, 11:20pm
I'm thinking strategically the best plan for gold is to swarm the c6 trap, rotate out the camel, bring the camel to the f3 trap, rotate out the elephant.  If this happened gold would be clearly winning, but it still wouldn't be ideal because a gold camel at f4 would be vulnerable to capture in the f6 trap unless the gold elephant stayed nearby.

Another plan is to swarm c6 and contest it.  I don't see any tactics that let us do that in the immediate future though.

I was trying to understand lightsharp's step rc8e.  The order of this step is weird. (A human would have made the three steps on the f file together.)  One possibility is it's needed for goal defense.  Another possibility is that after aaaa's move 14g Dd2n Cc2e Dd3n Dd4n it would only take silver two steps to complete an e7 phalanx:

14g Dd2n Cc2e Dd3n Dd4n
14s cd7e rd8s X X

Now the gold dog is completely locked out of getting to f7, where it would be a huge pain in the neck for silver to dislodge.  The fact that silver (maybe) is taking action to prevent a gold dog on f7 means (maybe) this is something silver is worried about.

Here's something fun:

14g Mf5 : Dg5
14s Mc5 : Hc6x
15g Ed5 Mf4

I want Dd5 Cd2 to be right but I fear without a plan to pull-and-replace the d6 dog the advanced dog will just turn into a liability.

Right now I'm leaning towards Ra5 X, because swarming c6 seems good strategically and I don't have any bright ideas tactically.
Title: Re: 2015 move 14
Post by SilverMitt on Jan 20th, 2016, 3:04pm
I don't see anything to do here first aside from blockading b5.  The point of bringing more pieces east would not be to get the horse free so much as possibly being able to attack around f6 more quickly.  The ce1 steps have the additional bonus of possibly switching the idea to rotate the e2 dog out, though I might like to play 14g a4 b3 rather than 14g b3 ce1.  I like keeping a5 free before we complete the blockade, so that silver couldn't push the b5 rabbit to b4 (without a rabbit on a5, we could typically play Ha5:R in response).

Meanwhile, the order of the steps in silver's move seems irrelevant.  The cd8 step is useful if silver's planning something like Hc7 cb7 next move.

That said, by now we're committed to having the camel on c5 and I still feel it's losing long-term.
Title: Re: 2015 move 14
Post by Hufflepup on Jan 20th, 2016, 4:36pm

Quote:
I disagree about the fight at c6.  I don't see silver sacrificing the horse without first playing Mb5 to make the capture of our camel inevitable.  Otherwise we can still withdraw the camel in some way resulting in a horse trade, and we get two moves to threaten new pieces while he cashes in the horse and then rabbit.  I also see a lot of potential to diamond-cover the c6 trap with silver pieces to delay capture of the horse or rabbit since silver would have no place to end with the camel.


I don't think the silver camel coming to b5  is a threat at all because it abandons the horse hostage, and we would have time to preemptively retreat the camel before the elephant could come across.
Title: Re: 2015 move 14
Post by half_integer on Jan 20th, 2016, 8:48pm
Are you not worried about silver re-hostaging the horse on b6 if our camel leaves c5 after silver Mb5?  Putting a silver rabbit on a6 only seems to help this re-hostaging (for instance, Ha5:R can be flipped back to b6 and is frozen).

What do you think about putting our own rabbit on a6 with Hb6 Mc5 in case of silver Mb5?  The horse would not be frozen and silver doesn't have enough pieces to frame.  I think Ra5 Rb2 or some other mix of forward steps on the a and b files is the only move that allows this.

There seems to be emerging consensus for swarming c6.  The question is what is the best way to carry it out.  I also like the idea of rotating the e2 dog as a secondary objective.

Perhaps Rbb4 Rcd1?
Title: Re: 2015 move 14
Post by Hufflepup on Jan 21st, 2016, 5:47pm

Quote:
Are you not worried about silver re-hostaging the horse on b6 if our camel leaves c5 after silver Mb5?  Putting a silver rabbit on a6 only seems to help this re-hostaging (for instance, Ha5:R can be flipped back to b6 and is frozen).


Aside from advancing a rabbit by one square I dont think this would help silver much.


With Ra5 I think Dd2n would be stronger than Rb2n as it stops the silver d6 dog from diving into d3 which would be problematic. An extra rabbit step on the b wing wouldn't allow us to extablish a phalanx on the silver camel any faster if we decided to do this on 15g. Keeping the b file rabbit where it is would also give us a slightly stronger goal defence if the silver elephant switches wings on 14s.


On balance I think Ra5n Dd2n north is our best bet. Mainly because an advanced dog on d4 would just get in the way if silver switches wings next turn.

Can the poll be started soon so we dont lose more reserve?
Title: Re: 2015 move 14
Post by half_integer on Jan 21st, 2016, 8:36pm
I'm not worried about a silver dog on d3.  Capturing a dog for giving up the horse frame seems like a win to me.

I do see that if we advance a few steps, we could also potentially be closer to rotating the camel out in some lines.

I agree about the poll.  We seem to have the moves and we can continue to discuss merits as it runs.
Title: Re: 2015 move 14
Post by deep_blue on Jan 21st, 2016, 11:15pm
I'll start the poll today, when I am back at home (might be 12h from now).
Title: Re: 2015 move 14
Post by Hippo on Jan 22nd, 2016, 12:02pm
Silver's plan could be rather simple ... Rg5 rh5.
How would we prevent the rabbit loss?
Title: Re: 2015 move 14
Post by mattj256 on Jan 25th, 2016, 12:44am

on 01/22/16 at 12:02:36, Hippo wrote:
Silver's plan could be rather simple ... Rg5 rh5.
How would we prevent the rabbit loss?
1. I think silver's plan is to swarm the f3 trap, not capture the rabbit.

2. If silver played that move, it would still take him 5 steps to capture the rabbit.  That's plenty of time to either move our elephant to f5 or seek compensation elsewhere for the rabbit.
Title: Re: 2015 move 14
Post by Hippo on Jan 26th, 2016, 1:20pm

on 01/25/16 at 00:44:33, mattj256 wrote:
1. I think silver's plan is to swarm the f3 trap, not capture the rabbit.

2. If silver played that move, it would still take him 5 steps to capture the rabbit.  That's plenty of time to either move our elephant to f5 or seek compensation elsewhere for the rabbit.


I see 4 steps ... this is why cat is ready in trap ...
Title: Re: 2015 move 14
Post by mattj256 on Jan 26th, 2016, 3:58pm

on 01/26/16 at 13:20:34, Hippo wrote:
I see 4 steps ... this is why cat is ready in trap ...

Oh you're right.  I didn't see that.  Ok so if sharpvector plays that move we can either keep the frame or the rabbit but not both.  

As long as we have no advanced pieces near f6 that rabbit is going to be in an awkward position.  For what it's worth, I think our biggest problem is our limited control of c6, not the h5 rabbit.
Title: Re: 2015 move 14
Post by Hufflepup on Jan 26th, 2016, 5:27pm
15g: Cc2e Dd3n Dd4n Dd5e

Looks like it would save the rabbit.


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