Is a pin a tactic?

I was surprised to find yesterday that, according to Wikipedia, a pin is not a "tactic"!

"Although a pin is not a tactic in itself, it can be useful in tactical situations."

https://en.wikipedia.org/wiki/Pin_%28chess%29

However, multiple lists of names of tactical motifs I found include pins/pinning:

(1)

http://chesstempo.com/tactical-motifs.html

http://chesstempo.com/tactical-motifs.html#pin

(2)

https://www.chess.com/forum/view/general/list-of-tactics-from-palatnik-amp-alburt

(3)

https://en.wikipedia.org/wiki/Chess_tactic

Is that Wikipedia statement simply wrong? What exactly is a tactic? (https://en.wikipedia.org/wiki/Chess_tactic; https://en.wikipedia.org/wiki/Tactic_%28method%29) Why is a pin not considered tactic? Is it a tactical motif but not a tactic? Must a tactic be a *series* of moves, and is that why a pin cannot be a tactic? If the move that pins a queen against a king is not a tactic, then what *is* it?

I think a tactic implies a gain of material or a positional concession from the other player. While a pin may not immediately do either, there are situations where it can.

So, I would say that sometimes it is and sometimes it isn't 

Interesting. I think it depends on the situation. I would consider pinning a more valuable piece a tactic. Like pinning a queen or a rook to the king with a bishop. There are strategic pins also, like pinning a knight on c3 simply to prevent white from playing e4.

That sounds like a realistic answer to me. In other words, the person who wrote that

sentence wasn't completely wrong, just wrong part of the time. That person may have been thinking only of the most common pin, of a bishop pinning a knight to a king or queen, not as a fast win of material. Note that the Wikipedia page at the link Chess_tactic also has a message at the top saying that there are problems with the references on that page: that the statements aren't matched with specific references. We (I) have to remember that Wikipedia can't always be trusted as a completely reliable source of information.

blastforme wrote:

A tactic is a short term plan aimed at winning material or improving your position, or even delivering a checkmate, etc., or any other short term goal. It differs from strategy in that strategy is longer termed plans that implement tactics to ultimately end the game in your favour. You can use a pin to accomplish a tactic. So a pin is to tactics as tactics are to strategy. P

Thanks. That fits with the other opinions above. Yes, per that military tactics page, tactics are the actual means of carrying out a plan, whereas strategy is long-term and not yet connected to positively identifiable means of implementation.

That all fits with my own distinction between tactics and strategy: If you can see the line all the way to the end then it's tactics, otherwise it's strategy. So a bishop pinning a knight is strategic if it is planning to limit that knight's mobility for some undetermined length of time, but a bishop pinning a queen against a king is tactical because that's the actual means of winning material: the end of the line is in sight. Thanks for clarifying this, everyone. Since I'm working on my own "plan language," I'm paying careful attention to definitions right now.

A tactic is a short-term technique that can be used to forcibly gain a winning position or a drawing position.*  A pin can be used this way, so it is a tactic.  You can imagine forks and skewers that don't immediately achieve much, but they are still tactics.  I actually think pins (at least absolute pins) are the most forcing of all tactics since they narrow down your choice of moves simply by making some moves illegal. 

*Capturing a loose piece is also a tactic by this definition, and I'm fine with that.

 "Strategy is about ideas, tactics is about moves" - that's my favourite definition, I saw it in  one of forums here few years ago. Control of open file, kingside attack, simplification, outpost, weak color complex, king activation, principle of two weaknesses - that's strategy. "If I go here then he goes there" - that's tactics.

Then there are tactical patterns, motifs, forcing moves etc., but it is always concrete. So for me pin is defintely a tactic. It is concrete. It is forcing because it limits opponents choices.

Pin is a tactical theme (or motif), but not an actual tactic. Piling on a pinned piece is a tactical operation.

I have a question for those who think pin is not a tactic - is fork a tactic for you? What's the difference? Fork doesn't always win material - for example if one of forked pieces escapes with stronger threat or check.

pins and forks are themes. a tactic is like when you come up behind someone unnoticed and taser them.

 I shall try in my next OTB game

The fundamental building blocks of tactics are move sequences in which the opponent is unable to respond to all threats, so the first player realizes an advantage. This includes forks,skewers, batteries, discovered attacks, undermining, overloading, deflection, pins, and interference.^[1] The Encyclopedia of Chess Middlegames gives the following tactics categories: Double Attack, Pawns Breakthrough, Blockade, Decoying, Discovered Attack, Passed Pawn, X-ray Attack, Interception, Deflection, Pin, Demolition of Pawns, Overloading, Annihilation of Defense, Pursuit (perpetual attack), Intermediate Move, and Space Clearance.

well, the opponent can always try a swindle Reb, i mean who is to say the attacker can see more deeply into the quagmire anyway ?

That's exactly why I prefer to see tactics as any concrete move sequence during analysis and calculation. Tactical motifs just help us look for typical stuff.

I put some time into analyzing this, and came up with some definitive results that I'll post below. I also found out that pins are equivalent to skewers if you just change the relative values of the trio of pieces involved, and I also found out that both of these are similar to an x-ray attack if you substitute a square for a piece, but I'll get into those topics later, probably in my other thread on tactical motifs.

I used my own terminology and notation, except for the concepts of "absolute pin" and "relative pin," which I abbreviate as A and R, respectively. I've long considered that difference between absolute pins and relative pins to be a largely irrelevant academic distinction that is mostly seen in books for beginners, especially when mentioning Legal's Mate, and is not relevant to actual play, and my results confirmed my suspicion today, because the important categories that I derived were independent of absolute versus relative status.

In summary, I derived three important classes of true pins, one category of which is strategic, and two of which are tactical. Therefore existing chess terminology isn't very specific since it does not distinguish between these classes.

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1st attribute code: material outcome (assume the pinning piece is protected)
E = equal in material
W = win of material

2nd attribute code: shield type
A = active shield
P = passive shield

3rd attribute code:
A = absolute pin
R = relative pin

Generalizations to note, and notation conventions used here

   Each pin involves exactly three pieces: the pinner, the shield, and the target.
   Notation convention: Those three pieces are ordered left-to-right here. E.g., BNK.
   Pinners are only pieces with infinite force lines, namely B, R, and Q.
Knights cannot pin because they do not have straight force lines.
Pawns and kings cannot pin because their force line range of one square does not allow three pieces to become aligned.
   The trio of pieces involved in a pin must be in non-decreasing order to make tactical sense, otherwise there is no threat of win of material.
   "Passive shield status" depends on the type of pinner and type of shield.
When a knight is the shield, the shield is always passive because the pinner must have a straight force line whereas the knight does not.
When a queen is the shield, the shield is always active because the queen can strike along any direction of straight force line back at the pinner.
   Ascending order of piece game value is used here: N before B, B before R, R before Q, Q before K.
   Assume there may exist two queens on the side being pinned (i.e., that one pawn got promoted to queen).
   With the above constraints, there exist exactly 19 possibilities, listed below:

      code
      123

BNR   EPR
BNQ   EPR
BNK   EPA

BBR   EAR
BBQ   EAR
BBK   EAA

BRR   WPR
BRQ   WPR
BRK   WPA

BQQ   WAR
BQK   WAA

RNQ   EPR
RNK   EPA

RBQ   EPR
RBK   EPA

RRQ   EAR
RRK   EAA

RQQ   WAR
RQK   WAA

BNK

 

   Conclusions:

   BBx and RRx patterns are not of interest because in typical positions there is no pin in the usual sense, and in fact the pinning player is often at risk of losing material.
   The three attributes used here are sufficient to create eight very useful categories of pins, listed below in alphabetical order of the code followed by examples:

EAA: BBK, RRK
EAR: BBR, BBQ, RRQ
EPA: BNK, RNK, RBK
EPR: BNR, BNQ, RNQ, RBQ
WAA: BQK, RQK
WAR: BQQ, RQQ
WPA: BRK
WPR: BRR, BRQ

   In fact, the 3rd code is largely irrelevant to describing the character of the shield position, and if the 3rd code is removed, the following four very useful categories (with only the first two codes) result:

EA*: BBK, RRK, BBR, BBQ, RRQ
   Characteristics: Tactically irrelevant and probably strategically irrelevant since a normal pin does not exist and no material is threatened.
EP*: BNK, RNK, RBK, BNR, BNQ, RNQ, RBQ
   Characteristics: Strategically important since a normal pin exists and limits mobility of the shield piece.
WA*: BQK, RQK, BQQ, RQQ
   Characteristics: Tactically important since the pinner always wins a major exchange.
WP*: BRK, BRR, BRQ
   Characteristics: Tactically important since the pinner always wins the exchange.

   More generally:

EA*: irrelevant
EP*: strategic
WA*: tactical
WP*: tactical

   Therefore pins can be either strategic or tactical.

A relative pin is a discovered attack awaiting opportunity. For example, in a typical Legall's mate threat when Black does not fall into the trap by taking the queen, a bishop and knight are exchanged by each side and White nets Black's e-pawn.

Sqod, I have to disagree with you at some points. Below your text is in blue.

1st attribute code: material outcome (assume the pinning piece is protected)
E = equal in material
W = win of material

To what moment do you refer? Is it on next move after pin? After 2 moves? After 5 moves?

The trio of pieces involved in a pin must be in non-decreasing order to make tactical sense, otherwise there is no threat of win of material.

If both shield and target can't be protected that's not true:

EA*: BBK, RRK, BBR, BBQ, RRQ
   Characteristics: Tactically irrelevant and probably strategically irrelevant since a normal pin does not exist and no material is threatened.

This kind of pin can force an exchange which can be relevant both tactically and strategically.

EP*: BNK, RNK, RBK, BNR, BNQ, RNQ, RBQ
   Characteristics: Strategically important since a normal pin exists and limits mobility of the shield piece.

Can be tactically important too - for example it can lead to removal of a defender.

WA*: BQK, RQK, BQQ, RQQ
   Characteristics: Tactically important since the pinner always wins a major exchange.
WP*: BRK, BRR, BRQ
   Characteristics: Tactically important since the pinner always wins the exchange.

These pins do not always win material - one counterexample is when in case of relative pin the pinned piece escapes with check.

Usually I'm assuming here White is to move. However, you're getting deeper into detail that is not very relevant, in my opinion: these positions are intended to show only the absolute basics of the trio of piece alignments and do not consider Zwischenzug checks, the pawns that normally limit the ability to break pins, or any other realistic attributes of a position. I was hesistant even to put kings on the board in every position. The positions shown aren't meant to be taken literally as board positions, only to demonstrate certain piece alignments.

Then I'd consider the position a skewer, not a pin. It's interesting that a pin mathematically becomes a skewer at the exact point that two of certain of the trio of piece values become even. I was thinking of starting a thread called "When pin becomes skewer" to show that. Maybe I'll add a post later about this, on this thread. By the way, it seems I was wrong about skewers being the "opposite" of pins: I was going by what Palatnik's book said, but as I studied it more I see that that's not the case, and skewers have a number of extra considerations to consider.

Same answer as before: you're adding complications beyond the intent of the diagrams, which is merely to show the basic alignments of three pieces. Of course, what you say is true if you take the diagrams literally as real board positions.

Thanks for you observations and responses, though.

Sqod, thanks for your comments on my comments - it was a pleasure discussing this topic with you.