Once again, the X-Ray Attack Manifesto!

[alvarofrota]

People had said there is nothing about the linearity of the piece which suffer the x-ray attack in the Chess Tempo definition and people are right about it.

However, in Chess, an attack has two possible meanings:

a.) In strict sense, according to the very Law of Chess (Article 3.1) an attack is a threat to take an adversary piece. ("A piece is said to attack an opponent’s piece if the piece could make a capture on that square according to the Articles 3.2 to 3.8" [that defines the moves of each peace]. "A piece is considered to attack a square, even if such a piece is constrained from moving to that square because it would then leave or place the king of its own colour under attack."); and

b.) In broad sense, but conjugated with the first meaning, an attack also is a threat to defend a piece of yours, after that piece takes a piece of the adversary. One can call this a "second attack" on the same adversary piece. The same concept is valid for an square.

Having said that, a question arises: how is possible an attack through an adversary piece, as Chess Tempo definition states for an x-ray attack?

Firstly, only if the attack has the second meaning, “a threat to defend a piece of yours, after that piece takes an enemy piece”.

And, in order to do so, only if your piece and the enemy piece has the same line of action, as this allows an attack (in the second sense of the term) of your piece to a piece that is placed alongside the line of action of the enemy piece, but behind that piece, not in front of them.

This is reason of that precise example of x-ray attack is used in the “Tactical Motifs” page!

A knight blocks (more properly, interferes with) all attacks alongside the file, rank and diagonal where this piece is placed. This occurs because this piece has no line of action, as he jumps from one square to another. So, is simple impossible to exist an x-ray attack through a knight. The knight has to move in order to such attack appears "de facto", but the name of this action is clearance, not x-ray attack.

And person can not say "Yes, but I disagree with your concept of what is an attack". Simple because this is not my concept. It is the Article 3.1 of the Law of Chess.

So, the Chess Tempo definition of what is an x-ray attack AND the very concept of what is an attack enforces the necessity of collinearity of the line of action of the two pieces involved in an x-ray attack.

The term x-ray attack is largely used in Chess as a synonymous of "pression alongside a line". However, in the domain of Chess Tactics, the definition of such tactical motif should be very precise in order to allow people to learn and train.

So, if you utilize the definition without the appropriated concern, every pin, every skewer, most clearance, most discovery attack, and also any pair of linear piece doubled in a rank, file or diagonal (any battery), all of this will be tagged as an x-ray attack.

This is wrong, of course, but this is already occurring. We have plenty of pins and other tactical motifs and themes falsely tagged as x-ray attack. This confusion is messing our tagging system!

An x-ray attack is an x-ray attack!
A pin is not an x-ray attack!
An skwer is not an x-ray attack!
A clearance is not an x-ray attack!
A discovery attack is not an x-ray attack!
A battery is not an x-ray attack!

Aquele abraço!

Álvaro Frota

[tommylein1]

a x-ray attack has always an effect through an "enemy"-piece (not an own piece)?

if yes then can define this in the tag-description. it reduce the confusion at least with "discovery attack" and "battery".

[hot chocolate]

People had said there is nothing about the linearity of the piece which suffer the x-ray attack in the Chess Tempo definition and people are right about it.

Yes, they are right in making this point. But you still think the issue is not resolved.

However, in Chess, an attack has two possible meanings:

a.) In strict sense, according to the very Law of Chess (Article 3.1) an attack is a threat to take an adversary piece. ("A piece is said to attack an opponent’s piece if the piece could make a capture on that square according to the Articles 3.2 to 3.8" [that defines the moves of each peace]. "A piece is considered to attack a square,j? even if such a piece is constrained from moving to that square because it would then leave or place the king of its own colour under attack."); and

b.) In broad sense, but conjugated with the first meaning, an attack also is a threat to defend a piece of yours, after that piece takes a piece of the adversary. One can call this a "second attack" on the same adversary piece. The same concept is valid for an square.

Having said that, a question arises: how is possible an attack through an adversary piece, as Chess Tempo definition states for an x-ray attack?

Firstly, only if the attack has the second meaning, “a threat to defend a piece of yours, after that piece takes an enemy piece”.

And, in order to do so, only if your piece and the enemy piece has the same line of action, as this allows an attack (in the second sense of the term) of your piece to a piece that is placed alongside the line of action of the enemy piece, but behind that piece, not in front of them.

In the last sentence above, I think your words, "...only if..." are not well supported by your arguments.

This is reason of that precise example of x-ray attack is used in the “Tactical Motifs” page!

A knight blocks (more properly, interferes with) all attacks alongside the file, rank and diagonal where this piece is placed. This occurs because this piece has no line of action, as he jumps from one square to another. So, is simple impossible to exist an x-ray attack through a knight. The knight has to move in order to such attack appears "de facto", but the name of this action is clearance, not x-ray attack.

And person can not say "Yes, but I disagree with your concept of what is an attack". Simple because this is not my concept. It is the Article 3.1 of the Law of Chess.

So, the Chess Tempo definition of what is an x-ray attack AND the very concept of what is an attack enforces the necessity of collinearity of the line of action of the two pieces involved in an x-ray attack.

Disagree. How do you justify this claim? I think you tried to justify this claim by pointing to the illustrated example on the tag description page. But one example does not justify your claim. It is just one example. And if a second example were to be added to the tag description web page, then I expect you would be unhappy if a knight on c6 were to be used to illustrate the X-ray tag.

The term x-ray attack is largely used in Chess as a synonymous of "pression alongside a line". However, in the domain of Chess Tactics, the definition of such tactical motif should be very precise in order to allow people to learn and train.

So, if you utilize the definition without the appropriated concern, every pin, every skewer, most clearance, most discovery attack, and also any pair of linear piece doubled in a rank, file or diagonal (any battery), all of this will be tagged as an x-ray attack.

This is wrong, of course, but this is already occurring. We have plenty of pins and other tactical motifs and themes falsely tagged as x-ray attack. This confusion is messing our tagging system!

Aquele abraço!

Álvaro Frota

Does anyone have any suggestions about how the tag can be improved?

http://www.fide.com/component/handbook/?id=171&view=article

[rombelstielz]

another war about X-rays, skewers, dogs and cats? 

[sotimely]

I have done 3700 problems on CT and I have yet to see an X-Ray attack. To me it is a mythical creature. Whenever I see the tag I don't understand why. I guess it's some kind of pressure on a piece that you will force to move, so you can hit what's behind it? But isn't that a pin? So yeah, I've read the motifs a couple times and wikipedia, a couple beginner's books, and I still don't know.

[alvarofrota]

Olá sotimely!

Some users thinks that any pin and skewer or even any discovery attack or any clearance are a an x-ray attack and they make a lot of noise about this tactical motif trying to prove they are correct.

But they are wrong and the only thing they achieve is to make difficult the comprehension of what a x-ray attack really is.

Try to read my comments in the following problems. Perhaps they will enlighten you about the x-ray attack tactical motif.

96741

153828

12041

13701

41235

72856

If you want, I can post more links with problems in which I made some comment about the x-ray attack in a given position.

Aquele abraço!

Álvaro Frota

[alvarofrota]

Olá sotimely!

Perhaps a better explanation is in my comment of problem 44004.

Abraço!

Álvaro

[sotimely]

Okay, based on 440044, it looks to me like an X-Ray Attack is when you have a double attack on a singly defended square (or 3 on 2, and so on) but only when counting an attack that passes through another piece, which works because as a result of the initial capture(s), you get a position where a piece is defending your attacker which has captured, but through the very attacker itself (the knight on e1 is defended by the rook at e8, "through" the white rook also on e). This pattern in effect is just like a counting problem, but this kind of attacker is trickier to count because "normally" attacks cannot be counted if they go "through" pieces. X-Ray Attack knowledge deals with those cases when they do count. Am I getting it now?

[alvarofrota]

Olá sotimely!

Yes, you understood perfectly the idea.

The key of the definition of the tactical motif "x-ray attack" is the term "attack", which, in its turn, is defined by the very "Law of Chess".

Some grandmasters, however, use the expression "x-ray" as equivalent of "pression along a line", mostly in strategical context. This is correct, of course, but the problem begins when some Chess Tempo users try to convert this usage to the tactical context, messing up any pin, skewer, discovery attack, clearance and also various forks as if all of them should be some kind of an "x-ray attack".

Aquele abraço!

Álvaro Frota

[prairiedoc]

I made a similar explanation for attack and defense in the comments to problem 73297.

[interlist]

I look in once and awhile.  

I still maintain, over these many years, the X-Ray family is a good concept.

And the X-Ray concept is more general than the familiar co-linear version, often being the essential driving dynamic of many tactics.

The most correct way for <CT> to handle this would be generalize the tag, or rather add the more specific versions.

Otherwise, perhaps we could divide into camps, dividing the tag-voting up so we can accommodate the differing points of view.

I don't think one-size-fits-all works. I hate the giant trash-heap that Clearance has become due to the conflation of X-Ray with the more correct concept. That's a consequence of the lack of needed specificity.  

Anyways, I always point to written works by Seirawan, McDonald, Weteschnik, etc which utilize the more general viewpoint. Plus, the historical Harkness definition embraces the general concept of any attack through a piece (or pieces).

[sotimely]

I think the name of this tag is part of the confusion. The word "attack" just seems like a generic noun to make the term about a move rather than an extremely necessary word to differentiate it from x-ray ideas in general. It's not just some x-ray tactic (which is how one might assume when they encounter the term "x-ray attack" without thinking about it). It's an attack that's hard to see because it's an x-ray. It's a position where you might fail to count one of the attacks because it passes through something, so you might not realize it actually counts.

All tactics revolve around things that are, at first, hard to see. They're different types of illusion. The x-ray attack, if I have understood it correctly now, is when an attack uses the same line that an opponent's uses, thereby being harder to see correctly because it looks like the opponent's piece blocks the attack, but it does count in the end because after a series of exchanges the "blocking" piece will not be able to recapture because the "x-ray" would capture it.

If I've understood it correctly, could we call this "X-Ray Counting"?