Changing Komi to 6.5 Points
Matthew Macfadyen
The American Go Journal I just received reports a wide move towards 6.5
points komi.
Is it widely known that this makes a combination Chinese/ Japanese rule
set (like the AGA rules) harder to work?:
If you do Chinese style counting, and there are an odd number of what
the Japanese call dame points, then Black will gain one (Japanese)
point, and a player used to Japanese counting will make a one point
error in counting the game.
But there are an odd number of points on the board, so a simple parity
argument says that when this occurs the margin will be an odd number, so
the game might be moved from a 4 point Black win to 5, but not from 5 to
6, thus with 5.5 points komi a player used to Japanese counting does not
have to worry about losing due to the number of dame points being odd.
(This argument fails if there is a seki with an odd number of mutual
liberties e.g. one eye each, but the combination of that occurring and a
half point game in Black's favour is reasonably rare).
Fortunately, it is not too hard to handle this one in practice. With 6.5
Komi and AGA rules it is impossible for Black to win by 0.5 points, you
have to play for a 1.5 point win by Japanese counting.
--
Matthew Macfadyen <mat...@jklmn.demon.co.uk>
Barry Phease
Matthew Macfadyen wrote:
>
> The American Go Journal I just received reports a wide move towards 6.5
> points komi.
>
> Is it widely known that this makes a combination Chinese/ Japanese rule
> set (like the AGA rules) harder to work?:
>
better change it to 7.5 points then :)
--
Barry Phease
mailto:Bar...@es.co.nz
Hal Womack
BRING BACK JIGO ?
Chess is choked & constipated with draws. That has less to do with
us than tiger cubs have to do with squid.
Jigos [draws] are so rare that they're fun. How about resurrecting
them for social & tournament play both ?
As for increasing the komi from 5.5, who has the stats on the
black/white victory ratio ? How about an experimental tournament with a
9.0 komi ?
Honestly, I was thinking about this even before I just lost a game
on IGS by 0.5 point :)
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>'O'<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Matthew Macfadyen (Mat...@jklmn.demon.co.uk) wrote: : The American Go
Journal I just received reports a wide move towards 6.5 : points komi.
: Is it widely known that this makes a combination Chinese/ Japanese rule
: set (like the AGA rules) harder to work?:
[snip]
--
Hal 3-dan of Womack Enterprises: Student of Shusaku, Diego Rivera, Ho Chi
Minh, Paul Robeson, Madonna? & Sgt. York. E-mail: wom...@best.com | 24 hr.
tel.= 415/788-5701 | 310 Columbus Avenue #209 San Francisco CA 94133 | USA
Dr. Kuo-Chi Lin
Matthew Macfadyen (Mat...@jklmn.demon.co.uk) wrote:
: If you do Chinese style counting, and there are an odd number of what
: the Japanese call dame points, then Black will gain one (Japanese)
: point, and a player used to Japanese counting will make a one point
: error in counting the game.
: But there are an odd number of points on the board, so a simple parity
: argument says that when this occurs the margin will be an odd number, so
: the game might be moved from a 4 point Black win to 5, but not from 5 to
: 6, thus with 5.5 points komi a player used to Japanese counting does not
: have to worry about losing due to the number of dame points being odd.
Can someone confirm this theory? Personally, I do not think it is
correct.
Kurt
Robert Jasiek
Dr. Kuo-Chi Lin wrote:
>
> Matthew Macfadyen (Mat...@jklmn.demon.co.uk) wrote:
>
>[...]
> : But there are an odd number of points on the board, so a simple parity
> : argument says that when this occurs the margin will be an odd number, so
> : the game might be moved from a 4 point Black win to 5, but not from 5 to
> : 6, thus with 5.5 points komi a player used to Japanese counting does not
> : have to worry about losing due to the number of dame points being odd.
>
> Can someone confirm this theory? Personally, I do not think it is
> correct.
>
> Kurt
I am also surprised about this, but I am guilty of having supplied the
mathematical background for this as included at the end of the message.
So here is a sketch of a proof for the above:
Presumptions are OddBoardSize and EvenSekiParity and standard area komi
s(t) = 2t - 0.5; t positive natural numbers; e.g. 5.5 komi.
We are interested in smallest possible winning margins:
For Japanese rules: B+0.5 or W+0.5.
For area rules (like AGA): B+1.5 or W+0.5.
(Proof see inclusions.)
Now we want to observe the consequences of a last neutral point
possibly changing the Japanese result into another win under area
rules. A last neutral point conforms to 1 point, thus only
smallest Japanese winning margins are of interest. Theoretically
4 cases occur: Each possible smallest Japanese winning margin
combined with each possible colour for the last neutral point to
be got. Details:
(1) Japanese B+0.5, B last neutral point:
With area rules this gives B+1.5. Hence B remains the winner.
(2) Japanese B+0.5, W last neutral point:
This is not possible, proof see inclusions.
(3) Japanese W+0.5, B last neutral point:
This is not possible, proof see inclusions.
(4) Japanese W+0.5, W last neutral point:
With area rules this would be W+1.5. However, this is not
possible, proof see inclusions.
Hence the only possible case is (1). There the winner is the same.
So indeed in the most frequently occuring parity case players
used to Japanese scoring need not worry about last neutral points
with area rules.
-:)]
Further reasons to use standard area komi only are contained in the
inclusions below. Especially this means that 7.5 komi are much more
preferable than 6.5.
--
robert jasiek
http://www.inx.de/~jasiek/
Subject: Re: Why 5.5 komi???
Date: Fri, 23 May 1997 15:31:59 +0200
From: Robert Jasiek <jas...@berlin.snafu.de>
Organization: Unlimited Surprise Systems, Berlin
Newsgroups: rec.games.go
> As I know, in chinese counting system, giving 6 or 6.5 has the same
> effect
> as giving 5.5. Am I right?
> Xin Kang
No, you are wrong. Proof:
Let n be the number of board points. It is sufficient to consider
n being odd. For even n things are inverted.
For simplicity two representative types of area rule sets shall be
considered: that of AGA 1991 and that of Ing 1991.
Komi for AGA type use half points: k = 0.5, 1.5, 2.5,...
Komi for Ing type use natural numbers with black winning ties:
k = 0, 1, 2,...
Let a be the area winning margin on the board for black. (Negative
values are a win for white.)
Let w be the winning margin for black. By definition: w = a - k.
It is necessary to consider cases depending on BoardSizeParity,
SekiParity, Winner. The board can have an even or an odd number
of empty grid points that are not monochromely surrounded. (They
occur in odd "sekis".)
n odd, SekiParity even, black win:
----------------------------------
a = 1, 3, 5, 7,... is possible.
The interesting value for a is the smallest with a black win.
Then w is the smallest possible winning margin.
AGA: a = k + 0.5 + (k - 0.5) mod 2
Ing: a = k + (k + 1) mod 2
Example:
R k a w
AGA 5.5 7 1.5
AGA 6.5 7 0.5
Ing 6 7 1
Ing 7 7 0
n odd, SekiParity even, white win:
----------------------------------
a = 1, 3, 5, 7,... is possible.
The interesting value for a is the greatest with a black loss.
Then w is the smallest possible winning margin.
AGA: a = k - 0.5 - (k + 0.5) mod 2
Ing: a = k - 1 - k mod 2
Example:
R k a w
AGA 5.5 5 -0.5
AGA 6.5 5 -1.5
Ing 6 5 -1
Ing 7 5 -2
n odd, SekiParity odd, black win:
----------------------------------
a = 0, 2, 4,... is possible.
The interesting value for a is the smallest with a black win.
Then w is the smallest possible winning margin.
AGA: a = k + 0.5 + (k + 0.5) mod 2
Ing: a = k + k mod 2
Example:
R k a w
AGA 5.5 6 0.5
AGA 4.5 6 1.5
Ing 6 6 0
Ing 5 6 1
n odd, SekiParity odd, white win:
---------------------------------
a = 0, 2, 4,... is possible.
The interesting value for a is the greatest with a black loss.
Then w is the smallest possible winning margin.
AGA: a = k - 0.5 - (k - 0.5) mod 2
Ing: a = k - 1 - (k + 1) mod 2
Example:
R k a w
AGA 5.5 4 -1.5
AGA 4.5 4 -0.5
Ing 6 4 -2
Ing 5 4 -1
---------------------------------
Results:
- For each case and each area rule set two komi values are
equivalent.
- Consistency independent of SekiParity is only given with
standard komi s:
AGA: s(t) = 2t - 0.5; t positive natural numbers
Ing: s(t) = 2t; t natural numbers
- For AGA s = 1.5, 3.5, 5.5, 7.5, 9.5,..., for Ing s = 0, 2, 4,...
- Inconsistent komi change the smallest winning margins to a win
of the other player in case of odd SekiParity.
- With area rules the nearest a values for constant SekiParity
have a difference of 2. Thus with properly chosen k as to the
rule set the value of a is constant for all k with |a-k| <= 2.
--robert jasiek
http://www.inx.de/~jasiek/endrules.html
Subject:
Re: Use for dame
Date:
Sat, 21 Jun 1997 19:25:48 +0200
From:
Robert Jasiek <jas...@berlin.snafu.de>
To:
ML go-rules <go-r...@lists.io.com>
References:
1
> But alternate filling is starting to catch on in the domestic
> Japanese professional tournaments too. One reason may be the discovery
> that it provides a check on the result. With 5.5-point compensation,
> if the margin of victory is half a point, and if the neutral points
> have been filled alternately, then the winner is (almost always) the
> player who got the last neutral point.
Here a sketch for a proof is given.
def) Definitions:
n: # board points
k: komi
wt: winning margin for territory score
tB: # B points for score
tW: # W points for score
e: # empty board points
eB: # empty board points surrounded by B
eW: # empty board points surrounded by W
eN: # empty board points that are not surrounded
fB: # surrounded empty board points in B seki
fW: # surrounded empty board points in W seki
cB: # prisoners of B color
cW: # prisoners of W color
ms: # stones played during game
mp: # passes during game
sB: # B stones played during game
sW: # W stones played during game
pB: # B passes during game
pW: # W passes during game
D := eB - eW + cW - cB
Presuppositions:
0) Rules: Japanese 1989
1) n = 361 : ODD
2) k = 5.5
3) wt = 0.5
4) eN : EVEN at game end
5) fB = fW
6) pB = 1
7) pW = 1
Implications:
10) def => wt = | tB - tW |
11) def => tB = eB - fB + cW
12) def => tW = eW - fW + cB + k
13) def => e = eB + eW + eN
15) def => ms = sB + sW
16) def => mp = pB + pW
17) setup with empty board => eN : ODD at game start
18) (1) and setup with empty board => e = n = 361 : ODD at game start
19) (6), (7), (16) => mp = 1 + 1 = 2 : EVEN. This also means: no move
after any pass.
Now we show:
A) D is even in case of a B win.
B) D is odd in case of a W win.
C) D is even in case of the last played stone being B.
D) D is odd in case of the last played stone being W.
Then it follows: A <=> C AND B <=> D.
The details:
(A)
30) (3), (10) => wt = 0.5 = | tB - tW |
31) (30) and B win => 0.5 = tB - tW
32) (30) and W win => 0.5 = tW - tB
33) (11), (12), (30) =>
0.5 = | tB - tW | = | eB - fB + cW - eW + fW - cB - k |
34) (5), (33) => 0.5 = | tB - tW | = | eB - eW + cW - cB - k |
35) (31), (34) => 0.5 = eB - eW + cW - cB - k in case of B win
36) def, (2), (35) => 6 = eB - eW + cW - cB = D is EVEN in
case of B win.
(B)
40) (32), (34) => 0.5 = eW - eB + cB - cW + k in case of W win
41) (2), (40) => -5 = eW - eB + cB - cW is ODD in case of W win.
42) (41) => 5 = eB - eW + cW - cB = D is ODD in case of W win.
(C)
Presupposition:
50) The last stone of the game is played by B.
Implications:
51) (50) => sB = sW + 1.
52) (15), (51) => ms = 2*sW + 1
53) (52) => ms is ODD.
Now the parity changes during the game are analysed:
60) (17), (18) => At the game start eB = eW = cB = cW = 0,
so D is EVEN. Besides e = eN = 361 are ODD.
61) After the first move eB = 360 is EVEN, eW = cB = cW = 0.
So D is still EVEN.
62) Changes due to a B move: placing the stone: e -> e - 1;
then if capture of i W stones: eB -> eB + i for the i board
points of capture AND cW -> cW + i.
63) Net effect of (62) capture: D -> D + 2*i keeps its parity.
64) Changes due to a W move: placing the stone: e -> e - 1;
then if capture of j B stones: eW -> eW + j for the j board
points of capture AND cB -> cB + j.
65) Net effect of (64) capture: D -> D + 2*j keeps its parity.
66) (62), (64) => each succession of a B and a W move changes
without consideration of captures e -> e - 2 keeping parity.
67) (53), (60), (66) => e EVEN at game end
68) (4), (13), (67) => eB, eW either both EVEN or both ODD
at game end
69) (68) => The parity of eB - eW is EVEN and independent of
eN value at game end.
70) (53), (61), (63), (65), (69) => D EVEN at game end.
71) Removals after the game end behave like captures during
the game and do not affect the parity of D.
(D)
Prove as in (C) but now
72) last stone by W => ms EVEN => e ODD at game end =>
eB - eW ODD at game end => D odd at game end
-:)]
Feel free to present a generalisation for aribitrary komi, scoring
systems, board sizes, winning margins, SekiParities, single pass
occurances, monochromely surrounded empty points in sekis,
handicaps...
--robert jasiek
http://www.inx.de/~jasiek/rules.html
Matthew Macfadyen
Barry Phease <bar...@es.co.nz> writes
>
>
>better change it to 7.5 points then :)
>
Yes, that's exactly the point. Komi of 6.5 is badly behaved, and
sometimes turns out to be 7.5 when you didn't expect it to. I believe
the Ing foundation have collected statistics justifying their 7.5 komi
(any public references known?).
Maybe we'll have to put up with a few years' playing with
stochastic komi before 7.5 gets widely accepted.
Incidentally there is no easy mechanism to give a komi
equivalent to 6.5 in Ing rules.
Matthew M
--
Matthew Macfadyen <mat...@jklmn.demon.co.uk>
Geenius at Wrok
On Thu, 10 Jul 1997, Robert Jasiek wrote:
> We are interested in smallest possible winning margins:
> For Japanese rules: B+0.5 or W+0.5.
> For area rules (like AGA): B+1.5 or W+0.5.
Can anyone give a quick compare-and-contrast summary of counting schemes
(Chinese, Japanese, Korean, AGA, Ing)? Also, what IS Ing?
--
"I wish EVERY day could be a shearing festival!" -- The 10 Commandments
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
Keith Ammann is gee...@albany.net * "This must be what evil tastes like!"
www.albany.net/~geenius * Live with honor, endure with grace * Analects 2:24
Dan Schmidt
Geenius at Wrok <gee...@albany.net> writes:
| On Thu, 10 Jul 1997, Robert Jasiek wrote:
|
| > We are interested in smallest possible winning margins:
| > For Japanese rules: B+0.5 or W+0.5.
| > For area rules (like AGA): B+1.5 or W+0.5.
|
| Can anyone give a quick compare-and-contrast summary of counting schemes
| (Chinese, Japanese, Korean, AGA, Ing)? Also, what IS Ing?
Here's a really quick version:
Japanese: count territory (surrounded space). This is what IGS and
NNGS use.
Chinese: count area (surrounded space plus your own stones). One
effect is that you don't lose points by playing extra moves inside
your own territory. Although it is not immediately obvious, there are
many fewer paradoxes and weird situations when using Chinese rules
than when using Japanese.
Korean: I dunno.
AGA: count territory, but players exchange prisoners under some
situations (like passing, or placing handicap stones) in order to
make the results come out the same as Chinese. Plus the "superko"
rule: you cannot cause the board to be the same as any time in the
past.
Ing: count area (with a particular stylized method of counting involving
placing all your unplayed stones on the board), 8 point komi, plus a new
ko rule in which different kos are effectively combined into one big ko.
Plus the name of the game is now Goe, for some reason.
Ing (I don't know his full name) is a businessman and philanthropist
who has spent a lot of his life coming up with his new rules, and now
promotes them.
For all the Go rules info you could possibly want, look at Robert
Jasiek's page, <http://www.inx.de/~jasiek/rules.html>.
--
Dan Schmidt -> df...@harmonixmusic.com, df...@alum.mit.edu
Honest Bob & the http://www2.thecia.net/users/dfan/
Factory-to-Dealer Incentives -> http://www2.thecia.net/users/dfan/hbob/
Gamelan Galak Tika -> http://web.mit.edu/galak-tika/www/
Robert Jasiek
> Can anyone give a quick compare-and-contrast summary of counting schemes
> (Chinese, Japanese, Korean, AGA, Ing)? Also, what IS Ing?
Sorry, but it hardly makes sense to give a _quick_ comparison.
For a reasonable one please go to my page and link to everything
about game END rules. You will also find many diagrams.
(Modern Korean is virtually Japanese.)
--
robert jasiek
http://www.inx.de/~jasiek/rules.html
Jim Conyngham
> : the Japanese call dame points, then Black will gain one (Japanese)
> : point, and a player used to Japanese counting will make a one point
> : error in counting the game.
>
> : argument says that when this occurs the margin will be an odd number, so
> : the game might be moved from a 4 point Black win to 5, but not from 5 to
> : 6, thus with 5.5 points komi a player used to Japanese counting does not
> : have to worry about losing due to the number of dame points being odd.
>
> Can someone confirm this theory? Personally, I do not think it is
> correct.
>
> Kurt
Matthew Macfadyen's original message never made it to my news server,
so I can only comment on the part quoted here. But in any case,
here's my two cents worth:
Let:
W = white's area (Chinese count)
B = black's
D = dame
at the point just before the first dame is filled.
W + D + B = 19x19 = 361, which is odd
So if D is odd, then W + B must be even.
Therefore if W is odd, B is odd and vice verse,
so the margin (B-W) or (W-B) must also be even.
(When Matthew says "the margin will be an odd number", I'm not sure
if he is referring to the final score, or the score just before the
first dame is filled. If he meant the latter, I think he's wrong.
IMHO.)
If you assume that neither player has passed,
(or pass stones are used)
then the difference in area (at that point) must equal
the difference in territory, so both are an even number.
So, IF there are an odd number of dame,
AND black is ahead (on the board, just before the first dame is filled):
IF his lead is 4 or less, he has lost the game.
(If he plays the first dame, he increases the lead to 5 and
looses by 0.5 if komi is 5.5, by 1.5 if komi is 6.5)
IF his lead is 8 or more, he has won the game.
(If white plays the first dame, the lead is decreased to 7
and white wins by 0.5 or 1.5)
His lead can't be 5 or 7, because we've proved it must be even.
If his lead is 6 AND komi is 5.5 AND he's assuming Japanese counting,
(ignoring the dame) then he THINKS he's won.
But if white fills the first dame, his lead will
be narrowed to 5 and he's lost.
On the other hand, if his lead is 6 AND komi is 6.5 AND white is
ignoring the dame, then white thinks white has won by 0.5, but
he's wrong if black fills the first dame and increases the margin
to 7.
Matthew seems to be assuming that black always fills the first dame,
but I don't think that's correct.
So I conclude that the possibility of a mis-perception is there
no matter where you set the komi.
By the way, at last year's Go Congress, there was a motion on the
agenda to revise the AGA pass-stone rule. (It was voted down.)
I heard that the suggestion was made because exactly this kind of
misunderstanding occurred in a tournament during the previous year,
****>>>> under the current 5.5 komi rule <<<<****
Anyone from the rules committees care to comment?
--
Jim Conyngham
-----------------------------------------------------------------
"Obvious" is in the eye of the beholder
Robert Jasiek
> Let:
> W = white's area (Chinese count)
> B = black's
> D = dame
> at the point just before the first dame is filled.
What is the first dame? The first as soon as only dame and
defensive moves inside territory are left? Well, ok then, what
about considering the defensive moves inside territory in
your following text? You have omitted their consideration.
[...]
> so the margin (B-W) or (W-B) must also be even.
> If you assume that neither player has passed,
> (or pass stones are used)
> then the difference in area (at that point) must equal
> the difference in territory, so both are an even number.
Maybe I am just too tired now late in the evening (ahem
early morning i.e.), but why is it
obvious that the differences are equal? What is territory here?
(Including prisoners?)
[...]
> His lead can't be 5 or 7, because we've proved it must be even.
You have proven nothing of the kind. We only know of parity at the
moment of D definition.
[...]
> Matthew seems to be assuming that black always fills the first dame,
> but I don't think that's correct.
Important is the last dame to be filled. Then Matthew is correct.
Compare my proof in my last letter of this thread. Have you
understood the proof? Please point out its flaws!
> So I conclude that the possibility of a mis-perception is there
> no matter where you set the komi.
Not in the normal parity case, see my proof.
> By the way, at last year's Go Congress, there was a motion on the
> agenda to revise the AGA pass-stone rule. (It was voted down.)
> I heard that the suggestion was made because exactly this kind of
> misunderstanding occurred in a tournament during the previous year,
> ****>>>> under the current 5.5 komi rule <<<<****
Maybe it was an odd parity case, odd wouldn't it be?
> Anyone from the rules committees care to comment?
What, does the AGA have several rules committees?::..
David Gibbs
In article <5pvh17$9nl$1...@nntp2.ba.best.com>,
Hal Womack <wom...@best.com> wrote:
> BRING BACK JIGO ?
>
> Jigos [draws] are so rare that they're fun. How about resurrecting
>them for social & tournament play both ?
I've played in tournaments where Jigo is an accepted results --
the Ottawa (Ontario) open does this, as does, I think, some of the
Toronto (Ontario) tournaments. You might see one or two Jigo
results in all the games played, when they occur they are very
helpful in spreading the scores, and especially, the tiebreaker
scores.
-David
--
-David Gibbs
dag...@qnx.com
Matthew Macfadyen
Robert Jasiek's article seems to be extremely thorough, but perhaps
needs a little translating:
I now think that the story is, under AGA rules the final margin will be
an odd number before komi, so it can be 5 or 7 but not 6, and so 6.5
komi behaves the same as 5.5.
Except that if there is a seki with one mutual liberty (Jasiek
would insist on specifying ad odd number of such sekis), the argument
flips and the result will be an even number, so 6.5 komi might be a win
for White where Black would win with 5.5
My original worry was that in practice players of all
nationalities do Japanese style counting when assessing a game in
progress (I'm not absolutely sure of this, but I have asked several
Chinese pros without hearing of any other method) and that a komi of 6.5
sometimes misbehaves when using Japanese counting to guess the AGA
result.
This depends on what will happen when you do Japanese counting
in your head and find that Black is winning by 6. I used to think that
you had to count the dame points to decide whether or not Black will get
the last dame and round it up to 7.
But Jasiek seems to be demonstrating that you don't have to
count the dame: Black will always get the last dame in cases where the
Japanese result says 6, which means that 6.5 komi gives the same result
as 5.5 (Black wins) except that some Japanese players will feel cheated
when they have White.
And if there happens to be a seki with one eye each, then our
present system with 5.5 komi causes the 5 point margins to be rounded up
to 6, so you should count Japanese in your head assuming 6.5 komi.
The upshot sems to be that increasing komi by 1 makes very
little difference, but causes annoyance to people trying to count the
game more often that 5.5 or 7.5 would.
--
Matthew Macfadyen <mat...@jklmn.demon.co.uk>
--
Matthew Macfadyen <mat...@jklmn.demon.co.uk>
Barry Phease
> |
> | Can anyone give a quick compare-and-contrast summary of counting schemes
> | (Chinese, Japanese, Korean, AGA, Ing)? Also, what IS Ing?
>
> Here's a really quick version:
>
> Japanese: count territory (surrounded space). This is what IGS and
> NNGS use.
You should specify that Japanese counting soesn't count any points in
seki. (IGS and NNGS do count them).
>
> Chinese: count area (surrounded space plus your own stones). One
> effect is that you don't lose points by playing extra moves inside
> your own territory. Although it is not immediately obvious, there are
> many fewer paradoxes and weird situations when using Chinese rules
> than when using Japanese.
If you play points inside your own territory you may not lose points but
you are losing the opportunity to play moves that gain points which
amounts to the same thing.
>
> Korean: I dunno.
Same as Japanese (expect that some tournaments use 6.5 komi).
[AGA, and Ing rules description deleted to save space]
Dan Schmidt
Barry Phease <bar...@es.co.nz> writes:
| Dan Schmidt wrote:
| > Japanese: count territory (surrounded space). This is what IGS and
| > NNGS use.
|
| You should specify that Japanese counting soesn't count any points in
| seki. (IGS and NNGS do count them).
I thought that the Go servers don't count seki points, but Ing does.
I just played a game with a seki today on NNGS and I didn't think it
counted the points.
| > Chinese: count area (surrounded space plus your own stones). One
| > effect is that you don't lose points by playing extra moves inside
| > your own territory. Although it is not immediately obvious, there are
| > many fewer paradoxes and weird situations when using Chinese rules
| > than when using Japanese.
|
| If you play points inside your own territory you may not lose points but
| you are losing the opportunity to play moves that gain points which
| amounts to the same thing.
It's not quite the same thing, although yes, it's still usually bad to
play inside your territory for no reason :)
Under Japanese rules, if you play extra moves inside your own territory,
you lose a point AND you lose sente (which is probably worth much more
than a point). Under Chinese rules, you just lose sente.
The one time when it really matters is when you play a point inside
your territory instead of passing. Under Chinese rules, there is no
penalty for doing that but under Japenese rules there is. In fact, you
can reconcile the two systems, like the AGA does, by counting territory
Japanese-style but assessing a one-point penalty for passing, making a
pass equivalent in score to playing inside your own territory.
--
Dan Schmidt -> df...@alum.mit.edu, df...@thecia.net