Arimaa Forum - Print Page


    
      
        Arimaa Forum
        (http://arimaa.com/arimaa/forum/cgi/YaBB.cgi)
      

        Team Games >> 2009 One vs TheMob >> 2015 Move 5
        
(Message started by: harvestsnow on Aug 22^nd, 2015, 3:09am)

Title: 2015 Move 5
Post by harvestsnow on Aug 22^nd, 2015, 3:09am

4s was played a few hours ago:
4s rg8s dd7s hh6s rb8s

http://arimaa.com/arimaa/notconv/old/boardimg.php?orient=n&size=300&imgtype=jpeg&ranks=r1r1rr/rrc1dcrr/Hh1d2m/4E2h/3e/3M2H/R1CDDC1R/RRR2RRR

Title: Re: 2015 Move 5
Post by chessandgo on Aug 22^nd, 2015, 5:06am

We could play 5g Ee5w Ed5w x x to try to get a Hb6. If we do not play Rh2n, silve can dive into g3 with his camel: 5s mg6s mg5s Hg3e mg4s. If we have to move the Elephant to f4, we've lost time.

5g Ee5w Ed5w De2n Rh2n or 5g Ee5w Ed5w Rh2n Rh1n at least minimize the damage of m->g3. The former guarantees that you can use all 4 steps to pull and replace next move, the latter might let silver try 5s mg6s mg5s Hg3w mg4s to force us to use one step defending f3.

Silver can also start with 5s hb6e rb7s rb6s hc6w to prevent the pull and replace on b6. We have a lot of of options though (pulling the rabbit to a5, but silver should be helped by the exchange; diving into b7 with the Horse; handling the rb5 towards c3 ...).

I don't think flipping the caMel to d5 on 5s is a problem, we can always move to c6:
5g Ee5w Ed5w Rh2n Rh1n
5s ed4e Md3n Md4n ee4w
6g dd6e Md5n Md6w de6w

If we don't like E->c5, I fear we might have to move our caMel west soon. Maybe something like 5g Md3w Mc3w Rh2n Rh1n?

Title: Re: 2015 Move 5
Post by Algorias on Aug 22^nd, 2015, 7:48am

on 08/22/15 at 05:06:34, chessandgo wrote:

I don't think flipping the caMel to d5 on 5s is a problem, we can always move to c6

I agree that camel to d5 is not a problem (the 4th step of your 6g elegantly stops the elephant from further messing with the camel), but what about sharp flipping the camel to e4? Doesn't this mean that we need to spend 3 steps defending, e.g.

5g Ee5w Ed5w Rh2n De2n
5s ed4w Md3n Md4e ec4e
6g Me4e Mf4s De3s Rg1n

or perhaps

6g Me4e Mf4e Mg4e x?

This means silver gets to attack f3 faster than we can attack c6. Am I missing something obvious in this line?

Title: Re: 2015 Move 5
Post by PerkofBR on Aug 24^th, 2015, 2:11pm

I was thinking in:

5g Ee5w Ed5w Md3w Mc3w

That way we force silver either to defend c6 from our EMH attack, or to set his own EMH attack at f3, but in either case the a6 horse gives us the advantage.

Title: Re: 2015 Move 5
Post by SilverMitt on Aug 24^th, 2015, 8:56pm

Given sharp's rabbit steps, we are now essentially even on time, e.g., after 5g Mb3 De3 g2, we have 2 additional attacking steps with the Ha6 vs. Hh5, and aside from that, the only differences are in the rabbits on a1/b1 vs. e8/g7.

With the straightforward 5g Mb3 h3 h2 already mentioned by c&g, we keep the silver horse out of h3 while having our own already on a6. I think this would give us a slight advantage at this point. I don't think moving our elephant away from the silver camel is better than that, but perhaps we can wait to move our camel with 5g De3 h3 h2 g2.

Title: Re: 2015 Move 5
Post by Hippo on Aug 25^th, 2015, 4:53am

The pull and replace b6 requires 4 step when we start with Ec5, so there would be no step remaining for defense in that case.

What is wrong with Eb5 instead? With one defending step? (Probably camel flip would be problem with Eb5 so Mc3?)

It creates another threat ... to flip the horse near our camel.

I have not studied it deeper ... are we fine after
mg3 Hh3, hb5 Hb6 Ec5 Dd3?

Title: Re: 2015 Move 5
Post by ikalyoncu on Aug 25^th, 2015, 4:58am

on 08/22/15 at 05:06:34, chessandgo wrote:

5g Ee5w Ed5w De2n Rh2n or 5g Ee5w Ed5w Rh2n Rh1n at least minimize the damage of m->g3. The former guarantees that you can use all 4 steps to pull and replace next move, the latter might let silver try 5s mg6s mg5s Hg3w mg4s to force us to use one step defending f3.

I wonder if silver can try 5s mg6sss Hg3s as a response to the former 5g, after which it's not clear to me if we can use all four steps to pull and replace:

5g Ee5w Ed5w De2n Rh2n
5s mg6s mg5s Hg3s mg4s
6g Ec5w Eb5e hb6s Ha6e
6s ed4e De3s ee4s de7s
7g Ec5s Ec4e Ed4e Ee4e
7s hh5s Rh3s hh4s xxx

In this final position I feel silver achieved more than we did, but I'm not sure.

Finally, in general, I think we should be doing something with either our elephant or camel (maybe both) on 5g. I don't fancy moves that don't relocate at least one of these pieces.

Title: Re: 2015 Move 5
Post by browni3141 on Aug 26^th, 2015, 12:16pm

After 5g e5ww h2n h1n I would be wary of silver trying to make this a rabbit pulling game with a move like 5s g6ww h5s d4w, after which the pull and replace is dubious because of 6s d6n e6ww e7s where silver won't get a horse hostage, but gold's attack is shut down and silver has a rabbit pull in the resulting quiet position. Instead of the pull and replace I wouldn't want to pull a rabbit when we are starting the race from behind.

Right now my favorite move is some variant of 5g h2n h1n d3w. We have the advantage of Ha6 which silver can not quickly match. He will have to pull a rabbit. It is okay to abandon the idea that we want camel flexibility because h2n h1n prevents the silver horse's advance. We won't need our camel to defend.

I have been involved in a few games of this nature where I get Ha6 with Rh3 Rh2 and attack while the opponent must rabbit pull. I like the resulting positions for the attacker generally, but it's a close game depending on the circumstances. I think we have an advantage but it is quite tiny.

Title: Re: 2015 Move 5
Post by Hufflepup on Aug 27^th, 2015, 3:11am

Quote:

I'm concerned about this possibility as well. If we don't make a choice of what to do with the camel soon I suspect Sharp will force it on us.

I'm thinking Md3w Mc3w would allow us to threaten to pull and replace on b6 with the camel in the future, leaving our elephant freeer to threaten any silver advance on f3.

Maybe Md3w Mc3w Rh2n Rh1n?

Md3w Mc3w Ra2n De2n would be another possibility, shoring up f3, and bringing a rabbit forward to support an attack on c6. This would mean silver would be able to get a horse to h3 one turn earlier, but I'm not sure if this would make up for avoiding a rabbit pull.

Title: Re: 2015 Move 5
Post by chessandgo on Aug 27^th, 2015, 3:48am

on 08/25/15 at 04:58:38, ikalyoncu wrote:

Silver would be commited to f3 fr a few more moves, so something like M->c5 with the idea of threatening a capture in two moves looks reasonable. We'd need to analyze it more to see if silver can hold on to f3 without the elephant when we threaten capture.

Title: Re: 2015 Move 5
Post by chessandgo on Aug 27^th, 2015, 3:54am

on 08/25/15 at 04:58:38, ikalyoncu wrote:

Finally, in general, I think we should be doing something with either our elephant or camel (maybe both) on 5g. I don't fancy moves that don't relocate at least one of these pieces.

on 08/26/15 at 12:16:19, browni3141 wrote:

Right now my favorite move is some variant of 5g h2n h1n d3w. We won't need our camel to defend.

I agree with the general feeling that our caMel wants to go west, especially with Ec5 leaving so many opportunities for silver. I'm sold on the "we have both h3 and a6" argument. So what do we want to play as a 4th step after 5g h2n h1n d3w? Mc3w as proposed earlier? Avoiding a caMel pull to c4 might be convenient.

Title: Re: 2015 Move 5
Post by ikalyoncu on Aug 27^th, 2015, 4:27am

on 08/27/15 at 03:54:23, chessandgo wrote:

I don't mind silver spending three steps for pulling the camel to c4. It helps us develop in the west. So De2n maybe an alternative fourth step, as proposed earlier. I have something like this in mind:

5g Md3w Rh2n Rh1n De2n
5s ed4w ec4e Mc3n hh5s
6g Dd2n Cc2n Rc1n Mc4w
or
6g Dd2n Dd3w Mc4w Dc3w

Title: Re: 2015 Move 5
Post by Hippo on Aug 27^th, 2015, 6:57am

Please refute my Eb5 Mc3.

It seems to me it does not give silver enough time to attack f3. Seems nobody else likes it, but please argue.

Title: Re: 2015 Move 5
Post by chessandgo on Aug 27^th, 2015, 9:13am

on 08/25/15 at 04:53:17, Hippo wrote:

Maybe 6s h->f3. Also maybe 5s mf4 Hg4? I don't see a refutation, just a lot of possibilities for silver.

Title: Re: 2015 Move 5
Post by SilverMitt on Aug 27^th, 2015, 12:30pm

on 08/27/15 at 06:57:42, Hippo wrote:

Please refute my Eb5 Mc3.

It seems to me it does not give silver enough time to attack f3. Seems nobody else likes it, but please argue.

I think I wouldn't like this after even a simple 5s Ec5 Mg4 response. Our elephant is blocked along the 5th rank and we can forget about pull-and-replace; meanwhile, the silver camel is free. If we flip the b6 horse on 6g, silver can, at the very least, flip the g3 horse in response.

I am more or less in agreement with the idea of committing our camel west in tandem with the h3/h2 steps, but let me note again that we are not obliged to move it even to c3, particularly if we play the De3 step (I previously suggested g2 as the 4th step).

Title: Re: 2015 Move 5
Post by Hippo on Aug 27^th, 2015, 2:43pm

on 08/27/15 at 09:13:27, chessandgo wrote:

Maybe 6s h->f3. Also maybe 5s mf4 Hg4? I don't see a refutation, just a lot of possibilities for silver.

mg3 Hf3 allows one step defense with the pull and replace maneuver.
It seems to me mf4 is too ambitious and I would return Ef5 in response.

on 08/27/15 at 12:30:05, SilverMitt wrote:

I would welcome the trade as that leaves mh on one wing while our camel could easily go east and we would have even bigger space advantage in Ha6.

5s ec5 eg4
6g hb4
6s ec4 ha4/b3 mf4 Hg4

is what I would be more afraid

I agree leaving the center with phant looks strange.

Title: Re: 2015 Move 5
Post by chessandgo on Aug 28^th, 2015, 5:39am

on 08/27/15 at 14:43:43, Hippo wrote:

mg3 Hf3 allows one step defense with the pull and replace maneuver.
It seems to me mf4 is too ambitious and I would return Ef5 in response.

I meant 5s mg3 Hh3, 6g hb5 Hb6 Ec5 Dd3, 6s hh5sees.

And
5s mg6s mg5s mg4w Hg3n
6g Eb5e Ec5e Ed5e Ee5e
6s hh5s hh4s hh3w ed4s
looks fine for silver?

Title: Re: 2015 Move 5
Post by chessandgo on Aug 28^th, 2015, 5:45am

on 08/27/15 at 12:30:05, SilverMitt wrote:

I am more or less in agreement with the idea of committing our camel west in tandem with the h3/h2 steps, but let me note again that we are not obliged to move it even to c3, particularly if we play the De3 step (I previously suggested g2 as the 4th step).

So we're looking at:
5g De2n Rh2n Rh1n Rg1n
5s ed4w Md3n Md4e ec4e
6g De3e Me4s Me3w Md3w
?

As for the Rg1n step, I'm very ambivalent about commiting to the Rg2 Rh2 "rabbit structure". We might lose the g2 square for hostaging purposes, and I don't see an immediate advantage to having g2 occupied. If a possible phalanx on g2 is the idea, playing Cf2e Rf1n when appropriate might be more agreable than Rg1n Rf1e (better goal defense with a light piece on the g-file, better space flexibility wrt hostages on g2 ...).

It's hard to find a good 4th step if we don't move the caMel at least to c3.

Title: Re: 2015 Move 5
Post by SilverMitt on Aug 28^th, 2015, 6:19pm

Well, I don't think the 4th step is critical. So, we need one of De3/Mc3, and we could play both, of course.

Title: Re: 2015 Move 5
Post by browni3141 on Aug 29^th, 2015, 3:14pm

I tend to like the g1n step as well, but it's usually most urgent when the elephant doesn't intend to defend the east. It could just be a waste here. I think Md3w is bigger, and the camel might as well go all the way to b3?

Title: Re: 2015 Move 5
Post by half_integer on Aug 29^th, 2015, 3:46pm

In reading through the discussed possibilities, it occurs to me that we could use an a3 rabbit to aid refutation in some of our moves. I propose something like the following:

a2n Md3w h2n h1n
a2n g1n h2n h1n

The a3 rabbit can unfreeze the camel in case of a pull or flip to c4 while advancing at the same time and threatening to flood c6. I don't favor a De2n step because with the E on e5, a flip to e4 just becomes a 4-for-2 for silver.

I'm unsure which move above I would prefer. The post above stating we may not want to commit a rabbit to g2 makes sense to me. But, not moving the camel costs silver an extra step if he wants to flip, while saving us one. I just don't know what the best 4th step is in that case.

CaMel on b3 does have the advantage of making an immediate threat, whereas c3 or d3 takes another move to come into position. However, patience is often the best course of action.

Thoughts on refuting the suggested moves, or a better 4th step?

Title: Re: 2015 Move 5
Post by SilverMitt on Aug 29^th, 2015, 3:50pm

Without the De3 step and keeping the camel on d3, we might lose a bit of time if sharp just pushed the camel to e3, trying to cut it off from the west.

Title: Re: 2015 Move 5
Post by half_integer on Aug 29^th, 2015, 4:03pm

In the discussion of not moving the camel on move 4, we decided we were fine with that possibility and moving the camel to c4 in response. It depends what silver can threaten with the remaining two steps. mg6s hh5s threatens a horse hostage if we move our E west; however with the camel on e3 we could easily make it an EMH vs emh in the east instead (or MH vs. mh with EH vs. eh in the west). I'm sure there are better silver uses of those two steps though.

Title: Re: 2015 Move 5
Post by SilverMitt on Aug 29^th, 2015, 4:31pm

We could be fine with it strategically, but it still inconveniences us, while the other 4th steps are just the slightest conceivable gains.

Title: Re: 2015 Move 5
Post by half_integer on Aug 29^th, 2015, 5:26pm

So, what are your thoughts on
a2n Md3w h2n h1n as compared to
Md3ww h2n h1n

Title: Re: 2015 Move 5
Post by deep_blue on Aug 29^th, 2015, 7:34pm

I thought that De2n also had the idea of protecting f3. Silver will somewhen attack in the east and presumably place his camel on g3. So by playing De2n we already defend that and ensure that we got 4 steps next move (while its a sort of move we would need to play anyway, if silver plays mg3 or anything similar.
So I see nothing wrong with that step whereas the Ra2n while it might help in some lines doesn't seem to guarantee to help somewhen.

Title: Re: 2015 Move 5
Post by browni3141 on Aug 30^th, 2015, 1:00am

on 08/29/15 at 15:46:51, half_integer wrote:

The camel getting pulled to c4 is unlikely to ever be a problem for us. We can always free it with c2n c1n c4w or d2nn c4w and silver has only wasted time while we've improved our position.

Title: Re: 2015 Move 5
Post by Hippo on Aug 31^st, 2015, 6:15am

Oops, I was not at home and missed voting ... is poll started regularly or one should check mail frequently?

Title: Re: 2015 Move 5
Post by deep_blue on Aug 31^st, 2015, 11:30am

Hippo, sorry to hear that. :(
The poll was open for about 2 days. But someone please remind me for next move to create a list of candidates 1 day before the poll starts so that people can see the poll coming and also tell if they think some move should be included.

Link to poll results: http://civs.cs.cornell.edu/cgi-bin/results.pl?id=E_1e95a506fad06f40

I will later today write the results also in this thread, but right now I am a bit busy.

Title: Re: 2015 Move 5
Post by deep_blue on Oct 10^th, 2015, 5:22am

Detailed vote report:
Authorized voters: 24
Actual votes cast: 9

1. 5g Md3w Mc3w Rh2n Rh1n (Mb3 h1-h3)
2. 5g Md3w Rh2n Rh1n De2n (Mc3 h1-h3 De3)
tied 3. 5g Ee5w Ed5w Md3w Mc3w (Ec5 Mb3)
tied 3. 5g De2n Rh2n Rh1n Rg1n (h1-h3 Rg2 De3)
5. 5g Ee5w Ed5w Rh2n Rh1n (Ec5 h1-h3)
6. 5g Ee5w Ed5w De2n Rh2n (Ec5 Rh3 De3)
7. 5g Ee5w Ed5w Ec5w Md3w (Eb5 Mc3)

	1.	2.	3.	4.	5.	6.	7.
1.	-	6	8	9	9	8	9
2.	2	-	6	8	6	6	8
3	1	2	-	4	4	4	4
4.	0	0	4	-	4	4	5
5.	0	2	4	3	-	4	6
6.	1	2	3	3	2	-	4
7.	0	0	1	3	2	2	-

Voting rights had:
Algorias, arimaa_master, aurelian, browni3141, chessandgo, clyring, CraggyCornmeal, DeathCure, deep_blue, half_integer, Harren, harvestsnow, Hippo, Hufflepup, ikalyoncu, Knedlik, PerkofBR, phairland, RonWeasley, Samraku, SilverMitt, Skarn, supersamu, Therin8, Hippo.