MatPlus.Net

 Website founded by
Milan Velimirović
in 2006

23:19 UTC
ISC 2024
 
  Forum*
 
 
 
 

Username:

Password:

Remember me

 
Forgot your
password?
Click here!
SIGN IN
to create your account if you don't already have one.
CHESS
SOLVING

Tournaments
Rating lists
1-Oct-2024

B P C F





 
 
MatPlus.Net Forum General The arrival effect needs a name
 
You can only view this page!
Page: [Previous] [Next] 1 2 3 4
(61) Posted by Nikola Predrag [Friday, Oct 6, 2023 14:55]

Viktoras, we need discussions indeed.
And a meaningful discussion relies on proper questions and not at all on any answers/conclusions.
Critical relevant questions build various dimensions for the 'space' of a discussion, so that we could see things from various perspectives and develop a comprehensive understanding of some system and its essential nature.
Various dimensions present various essentially distinctive QUALITIES, it is not about geometry. If we don't recognize and distinct essentially different qualities, we get a blurred picture, often not aware of the blurriness. Apparent 'clarity' is deceiving and eventually a lie, if the clarity of qualities is lost.
The clarity of communication is not what we achieve if the quality of communication is critically over-reduced (for the 'sake of clarity').
The meaningful approach continuously puts quality before clarity.
Definitions are for the definitive things, for anything else we need reasonably precise DESCRIPTIONS and then live with remaining uncertanties.
'and then live with' is not a passive state of sticking to descriptions, it implies evolution.

We publish 'the originals' and we must not forget the meaning of 'original' - never.
It's a complete nonsense to approach to the originals from the perspective of definitions.
Defining original new creations before their creation???????

I hate writing even a couple of words and writing these posts is a terrible nightmare for me.
We need a relevant critical approach to the topic before juggling with any answers and conclusions.
APPROACH by asking CRITICAL RELEVANT QUESTIONS.

Thanks for your patience, I support your efforts and suggest rich descriptions that reveal and preserve the essence of the qualities.
 
   
(Read Only)pid=25397
(62) Posted by Dmitri Turevski [Friday, Oct 6, 2023 15:05]

@Viktoras
Thank you, this is a very interesting concept, it's different from how the HTT is defined in the HA glossary, isn't it?
How the correspondence between try and and solution is established? Is it required that the try and solution end in exactly the same position or else the try is hidden?
 
   
(Read Only)pid=25398
(63) Posted by Viktoras Paliulionis [Friday, Oct 6, 2023 18:23]

Unfortunately, the identification of hidden tempo-tries is only partially implemented in HA. The definition in the HA glossary describes how it is now implemented in HA, but not everything is written there.

To identify HTT, a simple heuristic is used (see definition), that is not always correct. HA also can identify unique HTT (HTT without duals). They are labeled "hidden tempo-try(unique)". Only mating moves are compared for searching them.

If we had a function that compares two phases and tells us if those phases are different or dualized, then we could detect not only all HTTs, but also all solutions with tempo play.
Unfortunately, even a human cannot always tell whether two solution lines are the same or different.
 
   
(Read Only)pid=25399
(64) Posted by Dmitri Turevski [Friday, Oct 6, 2023 23:13]

Makes total sense, I guessed as much.
What if instead of hidden/non-hidden there were three buckets of tempo tries: definitely hidden, definitely non-hidden and the rest?
Identifiable tempo(null) moves would fall into non-hidden, checkmates by different type of piece would go to hidden etc, and this classification is gradually refined?
 
   
(Read Only)pid=25400
(65) Posted by Viktoras Paliulionis [Friday, Oct 6, 2023 23:58]

There can be four groups:
1) hidden(unique),
2) hidden(not unique),
3) non-hidden,
4) unknown.

I think group 1 is the most valuable. I don't see much benefit from others.

There is one more problem. We have to identify all the tempo-tries, but there are often a lot of them (see your h#5 and version h#4). Currently, the program no longer searches for new tempo-tries if their number exceeds the specified maximum number.
 
   
(Read Only)pid=25401
(66) Posted by Dmitri Turevski [Saturday, Oct 7, 2023 16:38]

If written with the null move notation (??) there seems to be just one tempo-try in h#4:
1.?? Kd5 2.?? Kc6 3.Ke8 ?? 4.Bf8 Kc7#
 
 
(Read Only)pid=25403
(67) Posted by Viktoras Paliulionis [Saturday, Oct 7, 2023 20:26]

This is a tempo-try, corresponding to the tempo-maneuver in actual play. All other tries in this example are duals for this tempo-try. They are not hidden. Hidden tempo-tries are those that demonstrate a completely different play or mate.
 
   
(Read Only)pid=25404
(68) Posted by Viktoras Paliulionis [Saturday, Oct 7, 2023 21:01]

Sorry, in my method the "corresponding" tempo-try is the one with the least number of null-moves. In this case it would be the following:
1.Bd1 Kd5 2.?? Kc6 3.Ke8 ?? 4.Bf8 Kc7#

The tempo-try you mentioned is also "corresponding" in a sense, but it probably needs a different name.

From "corresp-tempo-try" we can determine the type of tempo play.
1.Bd1 Kd5 2.Bxa4 Kc6 3.Ke8 Bxa4 4.Bf8 Kc7#
It shows that 2.Bxa4 ... 3... Bxa4 is pure tempo maneuver (waiting) consisting of two moves.

In case of bSd1 instead of bBh6, we would have another "corresp-tempo-try":
1.Sb2 Kd5 2.Sxa4 Kc6 3.Ke8 ?? 4.Bf8 Kc7#
1.Sb2 Kd5 2.Sxa4 Kc6 3.Ke8 Bxa4 4.Bf8 Kc7#

It shows that 3...Bxa4 is pure (waiting) tempo move.
 
   
(Read Only)pid=25405
(69) Posted by Dmitri Turevski [Sunday, Oct 8, 2023 10:32]

 QUOTE 
They are not hidden

In post 53 you called tempo try in h#4 "hidden" :)
 QUOTE 
in my method the "corresponding" tempo-try is the one with the least number of null-moves

Is this the best possible interpretation? Naturally it feels that "1.Bd1(Sb2) ... 2.B(S)xa4 ... 3... Bxa4" is the tempo maneuver, not just "2.B(S)xa4 ... 3... Bxa4".
 
   
(Read Only)pid=25406
(70) Posted by Georgy Evseev [Sunday, Oct 8, 2023 13:02]

QUOTE
in my method the "corresponding" tempo-try is the one with the least number of null-moves

Valery Gurov & Georgy Evseev
Ukraine - Russie - Macedonie 2000-01
3rd Pl.

(= 5+5 )

h#4

1.Bh5 Bb7 2.Ke2 Ba6 3.Kf3 Bc8 4.Kg4 Se5‡
1.Ke2 Ba6 2.Kf3 Bb7+ 3.Kg4 Bc8 4.Bf3 Sf6‡

HA shows
"Tempo maneuver (wB, waiting, 3) × 2"
But, as declared, second solution should only contain one tempo move as second white move.
(I consider "Tempo maneuver" interpretation as more correct.)
 
   
(Read Only)pid=25407
(71) Posted by Viktoras Paliulionis [Sunday, Oct 8, 2023 14:23]

 QUOTE 
In post 53 you called tempo try in h#4 "hidden" :)

Thanks for noticing the discrepancy in my posts.

When I wrote about possible interpretations, I did not yet have an answer for myself which interpretation was correct. That's why I asked other people's opinions. At that time, I had not yet analyzed the tempo-tries provided by HA. Since HA did not show tempo-move in this problem (the reason in such cases is usually a "hidden tempo-try"), therefore, I indicated this assumption in my interpretation.

When, among all the tempo-tries, you found TT completely matched with the solution (thanks again!), I realized what the form of tempo is here.

True hidden TT is in your h#2. But even this may be disputed by some, since the mate is repeated.

 QUOTE 
Is this the best possible interpretation? Naturally it feels that "1.Bd1(Sb2) ... 2.B(S)xa4 ... 3... Bxa4" is the tempo maneuver, not just "2.B(S)xa4 ... 3... Bxa4".

The purpose of the proposed criterion is to show only the existence of a tempo-maneuver, i.e. determine the form of the tempo play, not the maneuver itself.

In general case "??...??...??" can mean either one tempo maneuver or three independent tempo moves. More analysis is needed to determine the full maneuver. In our case, we can reason as follows:

Single "??B...??A" means that move B enables move A.

If two TTs exist (??B...??A and ??C...??B...??A), and no others exist, it can be interpreted that C enables B and B enables A. In this case, C-B-A can be considered as one maneuver.

Everything seems simple when there is only one tempo move/maneuver. But problems arise when there are two or more. Therefore, it is important to find a tempo try with at least-number of nullmoves for each tempo move/maneuver.
 
   
(Read Only)pid=25408
(72) Posted by Dmitri Turevski [Sunday, Oct 8, 2023 16:51]

@Georgy
I'm guessing that is because in
1.Ke2 Ba6 2.Kf3 Bb7+ 3.Kg4 Bc8 4.Bf3 Sf6#
and
1.Ke2 Ba6 2.Kf3 ?? 3.Kg4 Bc8 4.Bf3 Sf6#
3...Bc8 are considered non-corresponding moves Bb7-c8 and Ba6-c8
 
   
(Read Only)pid=25409
(73) Posted by Georgy Evseev [Sunday, Oct 8, 2023 17:24]

@Dmitri

But this is the "classic" hesitation tempo.
Or does HA not mark such move as tempo?
 
   
(Read Only)pid=25410
(74) Posted by Viktoras Paliulionis [Sunday, Oct 8, 2023 17:35]

 QUOTE 
HA shows
"Tempo maneuver (wB, waiting, 3) × 2"
But, as declared, second solution should only contain one tempo move as second white move.
(I consider "Tempo maneuver" interpretation as more correct.)

That Ba6-Bb7-Bc8 is a waiting maneuver is shown by the following "corresponding" tt:

1.Ke2 ?? 2.Kf3 ?? 3.Kg4 ?? 4.Bf3 Sf6#

Also, there are no other tt with fewer null-moves like in the previous example, such as
1.Ke2 __ 2.Kf3 ?? 3.Kg4 ?? 4.Bf3 Sf6#
1.Ke2 __ 2.Kf3 __ 3.Kg4 ?? 4.Bf3 Sf6#

On the other hand, there are also two tempo moves on W1 and W2. The following corresp-tt show this:
1.Ke2 ?? 2.Kf3 Bb7+ 3.Kg4 Bc8 4.Bf3 Sf6#
1.Ke2 Ba6 2.Kf3 ?? 3.Kg4 Bc8 4.Bf3 Sf6#
They are inside a larger maneuver so HA ignores them.

Besides, these tempo moves are "mutually exclusive": if one is treated as a tempo, the other is not a tempo. This property can be determined also from tempo-tries.
If both tempo moves were independent, then the following tt would exist: 1.Ke2 ?? 2.Kf3 ?? ..., but it’s not there.
 
 
(Read Only)pid=25411
(75) Posted by Viktoras Paliulionis [Sunday, Oct 8, 2023 17:39]

 QUOTE 
But this is the "classic" hesitation tempo.
Or does HA not mark such move as tempo?

Internal tempo in h#4 is ignored.
Try h#3 without first move.

Here we see some dependence on history when determining "tempo/non-tempo".
 
   
(Read Only)pid=25412
(76) Posted by Viktoras Paliulionis [Tuesday, Oct 10, 2023 12:48]

Identifying the longest tempo-maneuver may make sense, but it can lead to ambiguities.

(= 3+6 )
h#4
1.Sb2 Kd5 2.Sxa4 Kc6 3.Ke8 Bxa4 4.Bf8 Kc7#

Here Bxa4 is a tempo move (1.Sb2 Kd5 2.Sxa4 Kc6 3.Ke8 ?? 4.Bf8 Kc7#), but Sb2-Sxa4-Bxa4 can also be interpreted as a tempo maneuver (1.?? Kd5 2.?? Kc6 3.Ke8 ?? 4.Bf8 Kc7#).
How to avoid ambiguity in determining the form of a tempo play?

The following position shows a tempo maneuver involving three pieces:
(= 3+7 )
h#4
1.b2 Kd5 2.Bxa4 Kc6 3.Ke8 Bxa4 4.Bf8 Kc7#

The tempo try "1.?? Kd5 2.?? Kc6 3.Ke8 ?? 4.Bf8 Kc7#" shows that b2-Bxa4-Bxa4 can be interpreted as a tempo maneuver.
 
   
(Read Only)pid=25414
(77) Posted by Georgy Evseev [Tuesday, Oct 10, 2023 14:45]

I think that in any case when both sides work on providing tempo move to any of them all the thematic moves should be united as a a single tempo manoeuvre.

I would like to point at the following problem.

Gyula BEBESI
2nd Pr., Memorial M. Jacobs, Problem 1957
(= 4+4 )

h‡4* (4+4) C+

1…Rxf3 2.Re5 Cd7+ 3.Rf5 Ce7‡
1.Rc5 Re4 2.Rd6 Rxf3 3.Re5 Cd7+ 4.Rf5 Ce7‡

The set play may be written is as 1.?? ?? 2.?? Rxf3 3.Re5 Cd7+ 4.Rf5 Ce7‡
 
   
(Read Only)pid=25415
(78) Posted by Viktoras Paliulionis [Tuesday, Oct 10, 2023 20:17]

This is an interesting position, because the end of the solution exactly corresponds to the set play, the mates are also the same.

There are three tempo-tries related with the solution:
1.?? ?? 2.?? Rxf3 3.Re5 Cd7+ 4.Rf5 Ce7‡
1.?? Ke4 2.?? Rxf3 3.Re5 Cd7+ 4.Rf5 Ce7‡ - corresponding to the tempo maneuver of bK.
1.Kc5 ?? 2.Kd6 Rxf3 3.Re5 Cd7+ 4.Rf5 Ce7‡ - corresponding to the tempo move of wK.
There are two independent tempo here.

It would be interesting to see a helpmate with three consecutive '??' in the middle of a tempo-try.
Solving programs usually do not show more than one consecutive '??', because two consecutive '??' do nothing but reduce number of moves.
In theory, there can't be a tempo-try with two consecutive '??'s unless there's a third one somewhere.
 
   
(Read Only)pid=25416
(79) Posted by Jacques Rotenberg [Thursday, Oct 12, 2023 19:55]

the line
"
1.?? Ke4 2.?? Rxf3 3.Re5 Cd7+ 4.Rf5 Ce7‡
"
Looks artificial : There is no reason why white should play 1. ?? Ke4
 
   
(Read Only)pid=25417
(80) Posted by Viktoras Paliulionis [Thursday, Oct 12, 2023 22:19]

The reason is to lose time (make a tempo move).

But the reason doesn't really matter. These are just virtual phases, that you can find, for example, using Popeye with the NullMoves option.
"??" means null move, i.e. skipped move.
Each phase with null moves has some meaning, you just need to be able to read it.
 
 
(Read Only)pid=25418

No more posts
Page: [Previous] [Next] 1 2 3 4

MatPlus.Net Forum General The arrival effect needs a name