Life In 19x19
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Swim's Reviews
http://lifein19x19.com/viewtopic.php?f=4&t=14223
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Author:  djhbrown [ Sun Aug 27, 2017 7:02 pm ]
Post subject:  Re: Swim's Reviews

Swim's review is here:
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3027817

Author:  Kirby [ Sun Aug 27, 2017 7:40 pm ]
Post subject:  Re: Swim's Reviews

djhbrown wrote:


Thanks, and welcome back... If I understand correctly, Swim recommends for white to play either: O5, P6, Q7, Q11, P11, or O11 in this position?

Image

Is that what you mean?

In the game, I played R10. The paper says:
Quote:
Attachments are excluded, following the heuristic adage: "do not contact the stones you are attacking".


Is this the only reason that Swim thinks that R10 is bad?

Author:  djhbrown [ Sun Aug 27, 2017 10:02 pm ]
Post subject:  Re: Swim's Reviews

Kirby wrote:
Is that what you mean?

The illustration is only a partial review; the fightback method proposes attacking a weak group or invading a moyo; methods of achieving the latter are discussed in "Swimming with Alphago"; disjunctive methods are not exclusive, but generate alternative areas for moves; the intersection of all proposed move areas would create a preferred list of candidates; i considered taking the analysis further, but as my main purpose was to get section 2 of the paper into print (section 3 is what Arthur Sullivan calls "mere corroborative detail, designed to lend verisimilitude to an otherwise bland and unconvincing narative"), i didn't bother. My guess is that if i did so, Swim might prefer green over red, at least until it started reading; and it is conceivable that Swim might end up preferring red over green, which at first glance looks slow, but letting black split white's two weak clusters might not be a good idea.

at the end of the day, Swim's deductions would be sent off to the jury, which might come up with a different move altogether - i considered feeding the position into Leela or Ray to see what they, as jury members, might propose as follow-ups (or as alternative initial candidates), but figured that if anyone wanted to see their probable moves, they could do their own checks. i recall that in https://www.youtube.com/watch?v=6XG9WWQjBk4&t=1202s&index=29&list=PL4y5WtsvtduqNW0AKlSsOdea3Hl1X_v-S
Swim came up with different moves to Leela.

Kirby wrote:
Is this the only reason that Swim thinks that R10 is bad?

Swim doesn't think R10 is bad, merely that it wouldn't be a good way to go about attacking R9. i can envisage the methods described in "Commonsense Go" suggesting R10 as a leaning attack feint as preparation of an invasion of the upper right, but again, a thorough analysis of the position wasn't my main motive for the paper.

Author:  djhbrown [ Sun Sep 03, 2017 4:24 pm ]
Post subject:  Review #2: Sweet FA

DeepZen (w) vs Fine Art (b), semifinal of 1st World AI Go Open, black to play.

Attachment:
dzfac2sgm.png
dzfac2sgm.png [ 9.92 KiB | Viewed 6134 times ]


Swim's assessment:

"black has 107 points of influence; white has 71. So black should play safe at 'a', 7 steps from strong black group 1 along a green line, to reduce white's centre moyo".

comment:

Uberdude reports that Fine Art played at 'b'
forum/viewtopic.php?p=222078#p222078

This is a terrible move - a beginner's error - trying to save two worthless stones.

Swim observes: "black group 5 is not important, it is much smaller than black's lead and although it does separate white 4 from white 3 and 5, white 4 is not weak, so there is no point attacking it".

How on earth could a program as strong as Fine Art (FA) make such a stupid move?
Answer: because, like its parent Alphago, FA has sweet FA idea what it's doing, relying on short-sighted deep search instead of understanding.

Author:  djhbrown [ Sat Sep 09, 2017 4:25 am ]
Post subject:  Re: Swim's Reviews

Uberdude's review of a review of Swim's review #1
https://www.reddit.com/r/baduk/comments ... o_and_god/

Author:  djhbrown [ Mon Oct 09, 2017 9:27 pm ]
Post subject:  Swim's Reviews #3

white to play...(don't tell if you know the "correct" answers, of which there are two)
Attachment:
113.png
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Author:  djhbrown [ Fri Oct 13, 2017 10:51 pm ]
Post subject:  Re: Swim's Reviews #3

Swim's preliminary perceptions (colour and shadow maps):
Attachment:
113cmdes3.png
113cmdes3.png [ 54.64 KiB | Viewed 5817 times ]

group qualitative strength:
a = alive = two eyes or one big eye that isn't a killing shape
s = strong = not a, but a big enough eyespace within the shadow map
w = weak = not(a or s) and without a clear path to a wide open space
- = unknown (= not(a or s or w))

Black group 1's colour/shadow map has 5 points, but it has no eyes (G15 is not an eye because H15 is not colour-controlled by black). You can read that G12 and E14 are miai to connect black 1 to black 8; Swim will have to read that too; meanwhile, it regards black 1 as weak, so its 5 points aren't counted in black's total.

White 5 doesn't have two clear eyes (black can close its potential eye on the side), but it has 6 internal colour-controlled points, so - before reading - Swim thinks it is strong.

.. to be continued

Author:  djhbrown [ Sun Oct 15, 2017 12:27 am ]
Post subject:  Re: Swim's Reviews #3

Assuming komi is 7.5, white leads on the board by 11.5 - and it's white's turn. Being on move is worth komi, so white effectively leads by 19.

Code:
let lead = value(me) - value(you);
if lead + chance > 0 then playsafe
                     else fightback

value(x) =  sum over x.g of size(area(g))*(if weak(g) then 0 else 1)
            + captives(g)
            + if white(x) then komi

chance =  h(size(neutral space))

Swim decides white should playsafe.
Code:
to playsafe
    do foreach me.group
            if me.group is weak and
               me.group is important
            then save(me.group))
     or foreach you.group
              If weak (you.group) and
                 you.group is important
              then attack(you.group)
     or foreach me.moyo
              expand(me.moyo)
     or foreach you.moyo
         if wideopen(you.moyo)
         then invade(you.moyo)
         else limit(you.moyo)

x is important =  big (x) or (x splits (y,z) and
                  (y is important
                     or
                   z is important))

big (x) =  (value(save(x)) - value(tenuki(x))  > chance)
Attachment:
113cmdes3.png
113cmdes3.png [ 54.64 KiB | Viewed 5784 times ]

white has 4 weak groups: 2,4,6 and 9
Code:
if me.group is weak and
               me.group is important
            then save (me.group))

x is important =  big (x) or (x splits (y,z) and
                  (y is important
                     or
                   z is important))

big (x) =  (value(save(x)) - value(tenuki(x))  > chance)

white 2 doesn't split black 1 and 8 (they can connect at G12)
white 4 splits black 2 and 3, but neither is weak
white 6 splits black 4 and 5, but neither is weak
white 9 splits black 4 and 6, but neither is weak

so none of white's weak groups is doing something important and worth saving at this stage

... to be continued

Author:  djhbrown [ Fri Oct 27, 2017 10:26 pm ]
Post subject:  Re: Swim's Reviews

Black 1 is weak; black 4,6,7,8 are unsettled. Black 1 has two paths to black 8: G12 and {E13,E14,F14]. White's playsafe purpose in attacking a weak group is not to kill, but to force a defensive move. Here, white G12 would force black to capture F13 to connect, so G12 would expand white 3 in sente.

Alternatively, a move on any of the green lines, or a leaning attack on C8, would expand white's moyo between white 3 and white 8
Attachment:
113cmdes3wsl.png
113cmdes3wsl.png [ 58.92 KiB | Viewed 5678 times ]
..... to be continued

Author:  djhbrown [ Sat Jan 27, 2018 10:37 pm ]
Post subject:  Re: Swim's Reviews

review continuation:
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3071677

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