Author |
Topic: Move 41 (Read 8334 times) |
|
The_Jeh
Forum Guru
Arimaa player #634
Gender: 
Posts: 460
|
Chessandgo chooses 41g Ed3e Da3n Da4n Da5n. This is a move we had mentioned.
The move I had in mind at the conclusion of the last thread was 41s ef4w Hg4w dg3n ce6w.
|
| « Last Edit: Oct 5th, 2008, 12:22pm by The_Jeh » |
 IP Logged |
|
|
|
warren
Forum Guru
Arimaa player #2145
Gender:
Posts: 144
|
 |
Re: Move 41
« Reply #1 on: Oct 5th, 2008, 9:14pm » |
 Quote  Modify
|
Bomb suggests
41b Hg4n ef4e rb5e rc8w
threatening to capture his horse in 1 move and delaying the capture of our northwest cat. That 41b seems to lead to us getting his horse for our dog, leaving us with two extra rabbit but with two cats instead of his dog and cat.
|
|
IP Logged |
|
|
|
UruramTururam
Forum Guru
Arimaa player #2537
Gender:
Posts: 319
|
|
Re: Move 41
« Reply #2 on: Oct 6th, 2008, 12:02am » |
Quote Modify
|
My initial thought was
41b Hg4n ef4e rb5e rc8e
- which turned out to be quite similar to the Bomb's proposal. For the last step I assumed we can make a better use of this rabbit in the center, far from the gold dog.
|
| « Last Edit: Oct 6th, 2008, 12:04am by UruramTururam » |
IP Logged |
Caffa et bucella per attactionem corporum venit ad stomachum meum.
BGG Arimaa badges - get your own one!
|
|
|
warren
Forum Guru
Arimaa player #2145
Gender:
Posts: 144
|
|
Re: Move 41
« Reply #3 on: Oct 6th, 2008, 6:55am » |
Quote Modify
|
on Oct 6th, 2008, 12:02am, UruramTururam wrote:My initial thought was
41b Hg4n ef4e rb5e rc8e
- which turned out to be quite similar to the Bomb's proposal. For the last step I assumed we can make a better use of this rabbit in the center, far from the gold dog. |
|
An annoying counter to your "initial thought" is
42g Rd4wwn Da6n
threatening goal. Isn't it better to send our c8 rabbit west as in Bomb's suggestion to keep him from threatening goal?
|
|
IP Logged |
|
|
|
warren
Forum Guru
Arimaa player #2145
Gender:
Posts: 144
|
|
Re: Move 41
« Reply #4 on: Oct 6th, 2008, 7:07am » |
Quote Modify
|
on Oct 5th, 2008, 12:18pm, The_Jeh wrote:Chessandgo chooses 41g Ed3e Da3n Da4n Da5n. This is a move we had mentioned.
The move I had in mind at the conclusion of the last thread was 41s ef4w Hg4w dg3n ce6w. |
|
Bomb suggests a rather unhuman tactical counter to your 41s:
42g Ch3w Ee3e dg4nn Hf4e
That 42g seems to allow gold to escape without further loss of material despite leaving gold's elephant on the trap protected only by a cat.
|
|
IP Logged |
|
|
|
Fritzlein
Forum Guru
Arimaa player #706
Gender:
Posts: 5928
|
|
Re: Move 41
« Reply #5 on: Oct 6th, 2008, 7:22am » |
Quote Modify
|
on Oct 5th, 2008, 12:18pm, The_Jeh wrote:| The move I had in mind at the conclusion of the last thread was 41s ef4w Hg4w dg3n ce6w. |
|
On a first pass this move looks strong.
I don't want to trade our dog for his horse. Yes, CRR for D is a material advantage for us, but less than I was hoping for, and with a tense endgame to be played thereafter. I would not have advocated playing safe last move if I had thought we would have to trade horse for dog. If we eventually decide we have nothing better than this trade, we'll have to look back and wonder where we went wrong.
Therefore I approve of the step dg3n so that we win the horse without losing our dog. Note that 42g Ee3e Ef3e xxxx xxxx does not get chessandgo our dog for his horse, because we can answer with 42s Hf4n ee4e xxxx xxxx and get the free horse on 43s.
The down side of the dog retreat is that chessandgo's elephant is less firmly tied to the defense of the f3-trap. Supposing that he leaves his elephant on e3 in response to our move (as I expect he would), then we can't split our capture of his horse into two moves with 42s Hf4n ee4e xxxx xxxx, because his elephant can advance up the e-file to save his horse, and we don't have the immediate counter of capturing his cat with our dog to create a huge goal threat. In other words, this move is great for the control game because it is a serious threat to win a free horse, but bad for the racing game, as it may create situations where chessandgo can bail out with his elephant and win a goal race.
I would look first at 42g Ra2n Ra3n Ra4n Da6e. The goal-in-one threat means that we can't take the horse, which means that we can't get halfway there either. But using all four steps in the west with 42s rc8w rd5w rb5s rb4w might be adequate to insure that we can take his horse on 43s no matter what he tried to do in the west on 43g.
If instead chessandgo tries 42g Da6e Db6n cc7s Db7e, I am not sure that we can afford a defensive move. His dog would be eyeing f7, from where it would nullify our threat to his horse. Therefore I think we would have to take his horse on 42s in exchange for our cat, with the idea of using our elephant to put out the fire in the west on 43s. We would be ahead by two clear rabbits with, I think, as nice an endgame as we can hope for.
Chessandgo may have other, stronger tries, but at the moment I think The_Jeh's move wins us H for C, resolving the mess of the last many moves into a fluid position where it is (finally) quite clear that we stand better.
|
|
IP Logged |
|
|
|
Fritzlein
Forum Guru
Arimaa player #706
Gender:
Posts: 5928
|
|
Re: Move 41
« Reply #6 on: Oct 6th, 2008, 7:23am » |
Quote Modify
|
on Oct 6th, 2008, 7:07am, warren wrote:
Bomb suggests a rather unhuman tactical counter to your 41s:
42g Ch3w Ee3e dg4n Hf4e
That 42g seems to allow gold to escape without further loss of material despite leaving gold's elephant on the trap protected only by a cat. |
|
Oh, dear.
|
|
IP Logged |
|
|
|
Janzert
Forum Guru
Arimaa player #247
Gender:
Posts: 1016
|
|
Re: Move 41
« Reply #7 on: Oct 6th, 2008, 9:00am » |
Quote Modify
|
OpFor likes the same move as Bomb from depth 9 on till at least 15:
depth 15
time 39163
nodes 4558496223
qnodes 61287500
losing_moves 90
score 256
pv rc8w Hg4n ef4e rb5e w Rg1w Ee3n Ee4e Rh1w b rd5e re5s ce6s re4s w Ef4w re3w
Janzert
|
|
IP Logged |
|
|
|
The_Jeh
Forum Guru
Arimaa player #634
Gender:
Posts: 460
|
|
Re: Move 41
« Reply #8 on: Oct 6th, 2008, 9:03am » |
Quote Modify
|
on Oct 6th, 2008, 7:07am, warren wrote:
Bomb suggests a rather unhuman tactical counter to your 41s:
42g Ch3w Ee3e dg4nn Hf4e
That 42g seems to allow gold to escape without further loss of material despite leaving gold's elephant on the trap protected only by a cat. |
|
That is indeed unhuman. I had completely overlooked that possibility. However, it does not necessarily make me want to reject the move out of hand. For example:
42s ee4s ee3w rb5s rb4s
To lose material near c3 verges on fatal for c&g. Some choices he has are:
43g Hg4w Hf4w Rd4w Ef3w, to which we respond 43s ed3n He4n ed4e rb3s, and we win his horse after all, because responses to save it result in a forced goal for us, if I'm not mistaken. (Or if somehow it doesn't, we could just play dg5w instead of rb3s.)
43g Ef3n Ef4w Rd4w Da6s is easily thwarted by 43s rb3s ed3s Rc2n ed2w, 44g Rg1w Rf1w Re1w Rd1w, 44s Rc1e ec2s rd5e leads to a forced goal.
I'm shaken by my own lack of perception compared to Bomb in this instance, but Bomb could still be misevaluating a move that is actually good if we look a few moves deeper.
|
| « Last Edit: Oct 6th, 2008, 9:13am by The_Jeh » |
IP Logged |
|
|
|
camelback
Forum Guru
Arimaa perl monger
Gender:
Posts: 144
|
|
Re: Move 41
« Reply #9 on: Oct 6th, 2008, 9:11am » |
Quote Modify
|
How about this one. A possible goal threat.
41b rf7s rf6s rd5e ce6w
|
|
IP Logged |
|
|
|
RonWeasley
Forum Moderator
Forum Guru
Harry's friend (Arimaa player #441)
Gender:
Posts: 882
|
|
Re: Move 41
« Reply #10 on: Oct 6th, 2008, 10:00am » |
Quote Modify
|
I'm looking at
41b Hg4n ef4e rb5s ce6w
Gold must leave something to block our r on d5 so the gold E won't be too aggressive to save the H or advance the R on d4. Gold is trying to create a west side goal threat. Moving our r to b4 slows this down by creating our own additional goal threat. Moving our c to d6 makes the f6 trap defensable. The lack of mobility of the gold E keeps it from taking our dog while we secure the H. If the gold E gets blockers by threatening a d-H exchange (and move the dog to evade), the E can defend the H but now we have a dog around either c3 or f3 with threatening rabbits and a better goal race.
For some of the other suggestions, I'm not seeing the advantage of the rc8e step. It doesn't figure into any of my variations. If anything, rc8w is more useful in the future to defend a west side goal threat.
|
|
IP Logged |
|
|
|
Fritzlein
Forum Guru
Arimaa player #706
Gender:
Posts: 5928
|
|
Re: Move 41
« Reply #11 on: Oct 6th, 2008, 10:23am » |
Quote Modify
|
I'm not sure The_Jeh's line refutes warren's (Bomb's) refutation of The_Jeh's move.
42g Ch3w Ee3e dg4n Hf4e
42s ee4s ee3w rb5s rb4s
43g Da6s Da5s Da4s Ef3w
and we get a free rabbit, but it isn't immediately fatal to chessandgo because our attacking rabbit can be pushed back to b4 with a dog in front. The question is how good for us strategically that position with CRRR for H is.
When using Bomb in the endgame, we should be aware that it overvalues the horse. Right now, with H for CRR, Bomb thinks that Gold is ahead on material by +1, but if it trades horse for dog the material swings to -2, i.e. a two-rabbit advantage for Silver. This is not a typo: to Bomb's material evaluator, horse for dog is a three-rabbit swing.
If instead of forcing that trade, we had the option to capture a rabbit for free, Bomb's material evaluation would swing to -1. We get one point for the rabbit per se, and one extra point for the rabbit surplus in the endgame.
To my mind it's only slightly better to have CRR for D than to have CRRR for H, but in Bomb's material evaluation the former is much better. Bomb really puts a premium on that horse. Just so we are aware of the bias.
That said, Bomb did find a strong move I totally overlooked, so I definitely don't want to spurn its help.
|
|
IP Logged |
|
|
|
Janzert
Forum Guru
Arimaa player #247
Gender:
Posts: 1016
|
|
Re: Move 41
« Reply #12 on: Oct 6th, 2008, 10:25am » |
Quote Modify
|
After
41s ef4w Hg4w dg3n ce6w
42g Ch3w Ee3e dg4nn Hf4e
. 42s ee4s ee3w rb5s rb4s
OpFor suggests
depth 15
time 2803
score 26
pv Ef3w Da6e Ee3n Rd4w b ed3s rb3s rd5s rh7s w Db6s Db5s Ee4s Db4s b rh6s dg5w
Janzert
|
|
IP Logged |
|
|
|
The_Jeh
Forum Guru
Arimaa player #634
Gender:
Posts: 460
|
|
Re: Move 41
« Reply #13 on: Oct 6th, 2008, 10:57am » |
Quote Modify
|
on Oct 6th, 2008, 10:23am, Fritzlein wrote:I'm not sure The_Jeh's line refutes warren's (Bomb's) refutation of The_Jeh's move.
42g Ch3w Ee3e dg4n Hf4e
42s ee4s ee3w rb5s rb4s
43g Da6s Da5s Da4s Ef3w
and we get a free rabbit, but it isn't immediately fatal to chessandgo because our attacking rabbit can be pushed back to b4 with a dog in front. |
|
You're right. I can't think of any other lines, either.
|
|
IP Logged |
|
|
|
Janzert
Forum Guru
Arimaa player #247
Gender:
Posts: 1016
|
|
Re: Move 41
« Reply #14 on: Oct 6th, 2008, 11:55am » |
Quote Modify
|
on Oct 6th, 2008, 10:00am, RonWeasley wrote:I'm looking at
41b Hg4n ef4e rb5s ce6w |
|
OpFor continues with:
depth 14
time 4361
score -271
pv Rd4e Re4n Re5e Hg5e b eg4w Rf5n Rf6x ef4n ef5e w Da6e Rg1w Db6s Rh1w b dg3n Ch3w
It also considered 42w Rd4e Re4n Re5e Hg5n at depth 13.
Janzert
|
|
IP Logged |
|
|
|
|
Home
Help
Search
Members
Login
Register
Reply
Notify of replies
Send Topic
Print