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| (21) Posted by Nikola Predrag [Friday, Sep 29, 2023 01:37] |
Yes, of course, I described the whole maneuver. Direct purpose of W1 is sacrificial color-change (on the square), so that bS can move to that square (capturing the occupant of the opposite color).
There could be color-change with some other purpose (not sacrificial).
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| (22) Posted by Viktor Syzonenko [Friday, Sep 29, 2023 03:25] |
"Direct removal of a common obstacle"
"Прямое устранение общего препятствия"
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| (23) Posted by Dmitri Turevski [Friday, Sep 29, 2023 10:34] |
How many meaningfully different arrival effects of a black piece capture are there in orthodox helpmate anyway?
- robbing black of certain moving/attacking power
- gaining some moving/attacking power by making the square traversable
So, basically, the arrival effect is "capture" (deep helpmate analysis, yeah). If we want to single out the latter case, then "annihilation capture" seems most fit to me.
The fact that the term "annihilation" is already used for something that is not an arrival effect is totally fine - annihilation capture (effect) is part of the annihilation (maneuvre).
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| (24) Posted by Viktoras Paliulionis [Friday, Sep 29, 2023 11:11] |
In some cases, a capture may have no effect.
Helpmate Analyzer already uses an effect called "annihilation capture". In my top example, B2 arrival effect is an annihilation capture.
Do you think the arrival effects of W1 and B2 are the same?
QUOTE
The fact that the term "annihilation" is already used for something that is not an arrival effect is totally fine - annihilation capture (effect) is part of the annihilation (maneuvre).
In Helpmate Analyzer this is indeed the case: in the example there is an annihilation maneuver that starts in B2 (not W1), so the arrival effect of B2 is called annihilation capture. W1 is not a part annihilation maneuver (according to the definition of annihilation in the FIDE Album).
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| (25) Posted by Georgy Evseev [Friday, Sep 29, 2023 11:43] |
@Dmitry
Different white sacrifice motifs in h#3 (not just capture, but sacrifice capture), WinChloe numbers
898841 - King movement
895569 - Hideaway
893790 - Path clearance
834083 - Block replacement
740774 - Release piece
20894 - Sacrifice hideaway
18848 - Give tempo
17083 - Pawn removal
The list is not necessary full, the problems and names of effects are somewhat random...
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| (26) Posted by Dmitri Turevski [Friday, Sep 29, 2023 11:57] |
@Viktoras
I don't think they are.
W1 capture is purely to make the square traversable (for black). It also has anti-ziel arrival effect of making the square non-traversable for white, but that is not specific to capture.
B2 capture has two distinct arrival effects - to make the square traversable, but also to rob white of attacking power (to parry the check).
B2 also has additional arrival effects that are not related to capture (aiming the selfblock square).
@Georgy
I'm not sure we're on the same page here. Bigger scale motifs may vary to a large degree, but considering the basic arrival effects of a single move they either provide mobility or take away mobility (or are irrelevant, as Viktoras has noted).
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| (27) Posted by Viktoras Paliulionis [Friday, Sep 29, 2023 12:31] |
@Dmitry
In fact, all effects (not only captures) can be divided into two classes (actually, more, but the main two). But are those two types enough for us, or do we need a more detailed classification?
QUOTE
W1 capture is purely to make the square traversable (for black). It also has anti-ziel arrival effect of making the square non-traversable for white, but that is not specific to capture.
We can ignore second (negative) effect.
QUOTE
B2 capture has two distinct arrival effects - to make the square traversable, but also to rob white of attacking power (to parry the check).
You are right, there are two arrival effects here, but I think the first effect in B2 is different from W1. The arrival effect of W1 is immediate, while B2 does not open the required line, this move is just the first step to clearing the line.
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| (28) Posted by Dmitri Turevski [Friday, Sep 29, 2023 17:46] |
QUOTE
do we need a more detailed classification?
I don't know? It feels like if we want to decompose complex things into simple building blocks/effects we would want as few types of these as possible, but I could be wrong.
QUOTE
The arrival effect of W1 is immediate, while B2 does not open the required line
I'm not sure about this immediate/delayed argument. It's like saying that unguarding a square is different from removing a single guard from a double guarded square, which is also not immediate. B2 still removes the white piece from the line, it just also puts another piece there temporarily.
If I were to point at the difference, I'd say that W1 is about squares and B2 is about lines.
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| (29) Posted by Viktoras Paliulionis [Friday, Sep 29, 2023 23:04] |
QUOTE
If I were to point at the difference, I'd say that W1 is about squares and B2 is about lines.
Not necessarily, can be a square:
 (= 4+5 )
1.Sxf4 Be2 2.Sg6 f4#
In my opinion, neither of the two effects you mentioned are suitable for the following example:
 (= 3+6 )
1.Sxg5 Kc6 2.Sh3 Sd4 3.Rh5 Sf3#
Here the arrival effect of B1 (annihilation capture) doesn't make the square traversable.
NOTE: Now I'm starting to think the difference between effects "Annihilation capture" and "Unblock by capture" (I want to change this name) is that annihilation capture doesn't actually make the square traversable (the line or square remains blocked after capture).
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| (30) Posted by Georgy Evseev [Saturday, Sep 30, 2023 15:02] |
 (= 4+8 )
h#2.5
This position shows that original example has two separate arrival effects: removal of white mass _and_ path clearance.
Here we have a removal of white mass only - black have an alternate route to block square.
1...Rxd4 2.Bxd4 (Bc7?) Bc5 3.Be5 Be3#
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| (31) Posted by Viktoras Paliulionis [Saturday, Sep 30, 2023 15:49] |
What does the term "mass" mean? What is the difference from an "obstructing piece" or a "line (square) blocking piece"?
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| (32) Posted by Georgy Evseev [Saturday, Sep 30, 2023 16:16] |
"Mass" is generalized term, including both self-obstruction and self-interference.
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| (33) Posted by Viktoras Paliulionis [Saturday, Sep 30, 2023 22:07] |
@Georgy:
I don't recall other helpmate composers or judges using this term ("Mass"). I prefer more common terms like "capture of an obstructing piece".
The term "removal" is also ambiguous. In the Encyclopedia of Chess Problem, "removal" means departure or withdrawal (not capture), for example "removal effect" (=departure effect).
Instead of "removal", a more accurate term would be "removal by capture", but with more words.
Arrival/departure effects by Helpmate Analyzer for your position (I added wKa1):
W1 (Rxd4): Departure effect: Line opening for White
Arrival effect:
1) Unguard of mating square by capture,
2) Unblock by capture (need a more precise name).
B2 (Bxd4): Arrival effect: Annihilation capture
W2 (Bc5): Arrival effect: Ambush / reaching the mating square
B3 (Be5):
Departure effects:
1) Line opening for White,
2) Unguard of mating square
Arrival effect: Self-block
W3 (Be3#): Arrival effect: Check.
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| (34) Posted by Andrew Buchanan [Sunday, Oct 1, 2023 04:57] |
Naming things can be hard. I'd liked Shankar's "annihilate" - a pity it's already taken.
Maybe "Unblock by exchange"?
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| (35) Posted by Georgy Evseev [Sunday, Oct 1, 2023 10:51] |
@Victoras
Term "mass" is/was used (at least by some composers) in logical moremovers.
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| (36) Posted by Viktoras Paliulionis [Sunday, Oct 1, 2023 11:19] |
Yes, but mostly in direct-mates, not in helpmates.
I think the name "removal of mass by capture" could be suitable as a general name for the whole group of effects, but not for a specific effect.
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| (37) Posted by Viktoras Paliulionis [Sunday, Oct 1, 2023 14:42] |
The idea for identifying effects came from book Black to Play by Feather. He used terms such as "unguard by capture", "self-pin by capture", "self-unpin by capture" to refer to the effects.
I agree with Dmitri Turevski that at the most general level there are only two effects associated with capture. But his description of the two effects does not cover all cases. I think it would be more accurate to define them as follows:
- Elimination of attacking power of enemy piece by capture.
- Elimination of a line or square blocker by capture (perhaps "removal of mass by capture" would also be suitable).
Helpmate Analyzer identifies effects on a more specific level. It currently identifies the following effects associated with capturing pieces:
1. Eliminating an attacking power of enemy piece by capture:
1.1. Unguard of mating square or line by capture (=capture of a guarding piece).
1.2. Self-unpin by capture (=capture of a pinning piece).
1.3. Parrying the check by capture (=capture of a checking piece).
1.4. Check prevention by capture.
1.5. Unguard of flight square by capture (to allow own king move).
1.6. Unguard by capture to allow castling.
2. Eliminating a line or square blocker:
2.1. Capture of a blocker with a future leaving the square. The resulting positive effect comes from line-opening or vacation of the square.
Name in Helpmate Analyzer: Annihilation capture.
2.2. Capture (with sacrifice) to allow an opponent’s piece to move to previously occupied square.
HA name: Unblock by capture (I would like to change this name).
2.3. Capture (with sacrifice) to allow an opponent’s king to move to previously occupied square (special case of 2.2).
HA name: Capture of a blocking piece to provide a flight.
2.4. Capture allowing a future move of the same line-piece in the same direction.
HA name: Capture of an obstructing piece.
2.5. Self-pin by capturing a white blocker between the black king and the white line-piece.
HA name: Self-pin by capture .
2.1-2.4 have much in common but are also different. My example and question were about the specific effect 2.2.
I'm not sure about the other points either. I would like this classification to be complete and consistent. Any suggestions are welcome.
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| (38) Posted by Joost de Heer [Sunday, Oct 1, 2023 21:28] |
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| (39) Posted by Dmitri Turevski [Tuesday, Oct 3, 2023 17:46] |
QUOTE
2.5. Self-pin by capturing a white blocker between the black king and the white line-piece.
Is this really a separate capture specific arrival effect? Without capture it would be a combination of self-pin + check parrying, so with capture isn't it just a [pure] self-pin?
It looks like "Self-pin by capture" is defined by a lack of "Check parrying" feature, which is not consistent with how the HA usually works: lack of an effect is indicated by simply not listing that effect.
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| (40) Posted by Viktoras Paliulionis [Tuesday, Oct 3, 2023 21:55] |
I think this is a theoretical question, and the answer depends on the interpretation of what "Self-pin by capture" is. I agree that the captured piece can often be removed and the self-pinning will still work. But another interpretation is possible, that with "self-pin by capture" the White line blocker is replaced by the pinned Black one. We can choose which interpretation is better. I think the first interpretation does not apply to the following example:
 (= 6+4 )
h#1
1RQ4K/8/2p5/1P1P4/8/rk1P4/1r6/8
1.cxb5 (cxd5?) Qc4#
Is self-pin possible here without capture?
Helpmate Analyzer identifies "Interference/check parrying" and "Interference/self-pin" effects. But they are never shown together because "Interference/self-pin" can be considered a composite effect consisting of two effects. "Interference/self-pin" is not possible without "Check parrying", so I don't think it needs to be specified additionally.
According to the Encyclopedia, self-pin can be carried out in four different ways:
(a) indirect self-pin, by moving own King onto the pin-line;
(b) indirect self-pin, by removal of an own piece off the pin-line;
(c) direct self-pin, by capturing a front piece of opponent's battery aiming at own King;
(d) directly, parrying opponent's check by moving an own unit on the checking line.
Here, "self-pin by capture" is also distinguished as a specific way.
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