How can you deliver checkmate with a king?

Not in real life, but in chess, as any attack on the king is considered check, even if you "dont intend to capture the king on the next move". There is no "allowing" a check, the piece that moves causes check.

the pawn's movement causes check, it doesn't allow it, as every attack on a king is check.

Confusions about states.

Just as an opening statement - because that is not the subject of this post - I repeat the rather obvious statements on delivery of checkmate and of any game state:

1. The player delivers the checkmate (by law)
2. the checkmating move delivers the checkmate as well (by law)
3. When the checkmating move is a king's move - or counts as such through castling (in the laws) - then obviously the king delivers the checkmate. This is not literally in the law but if you deny this simple logical derivation you would also have to deny that a "bishop" captures a "queen" and only allow "the bishop's move captures the queen" and "the player captures the queen". Which, everyone will admit, is completely insane. From a logical perspective, the comparison is a 100% match.

The question though is not "how does (state) delivery work" but "how can somebody get totally confused about it?" The answer is already slightly visible in the above examples. Clearly the bishop knocks the queen off the board and upon delivery the queen is gone - in the NOW. But not the checkmated king as there is clearly some analysis to do to see it is in check and it cannot escape. That's the post-checkmate-analysis and the delusion is that it has something to do with the delivery of the checkmate.

That is an example, but the rules imply post-state-analyses on several places. The most dramatic ones are the dead positions (no checkmate is possible in any future) and the one-sided dead positions (after a player timing out). To know whether or not the position is a dictated draw you will need to play every possible line to find a possible checkmate. Only - you can't play them in the game you must play them in analysis. Which is the same as for checkmate and stalemate. Part of this analysis is looking at "squares under attack" but keep in mind that these only exist by virtue of applying the move rules to a piece at a point where the game has already ended! So it is virtual move-analysis, not legal play. And there are other moves which might shield the king unless they are pinned. And there is even the possibility to escape with an e.p. move which needs to be assessed. All require analysis without possible game play. The name for such states in computer science is "Look-ahead states".

Note that not all terminations are look-ahead states. The 3/5 repetition- and 50/75-move rules are "look-back states". They may require an inspection of the game record but one need not analyze moves into an unknown future.

Where does this lead to? Not to changing anything about the "delivery" of states which will always be the last move. But to point out that the pieces which feature in the post-state-analysis have a function to determine which state exist but - as play is over - cannot be attributed with any sort of delivery of that state - unless they played that role in the last move! That's it!

Except that's not true. The pawn moving does indeed "allow" check. In your diagram the pawn moving is not checking the other king is it? Instead, it's allowing the bishop to check the king. It's not causing a check (the bishop actually causes it because it's the source) just as the yellow car moving out of the way does not cause the collision. The two cars that collided cause the collision, and the checking piece and the king are the only two pieces involved in a check. At least that's what the rules say.

The rules for check (and checkmate) make no mention of the moved piece causing check, but they DO mention the attacking piece (in this case the bishop) and the king. So while there is no reason to believe a moving piece causes check, there IS a reason to believe the checking piece causes check. At least according to the rules.

In chess, allowing check is a move like this, that allows the move Rc2+

While causing, or giving, check is a move that checks the enemy king, like this move:

That move causes the black king to be put in check. It's a terrible move, I know, but it's just an example.

I perfectly agree with your second paragraph, but that's not what we're arguing about. As you seem to keep forgetting, check is different from checkmate. Checkmate is more than an attack on a king. If that was what checkmate was, then a simple check would be checkmate. Checkmate is an entire position, in which a king is under attack with no escape. So the piece that moves is the piece that causes the position to be checkmate. Meaning the piece that moves is the piece that checkmates. Simple logic.

Check and checkmate are identical, except for the one condition separates them. The king not being able to parry the check. There is nothing in the rules that say anything about an "entire position". And there is no reason it would even matter. Both check and checkmate are about the "entire position" so is any tactical move or any waiting move, so that doesn't have anything to do with what we are talking about. It would be hard to find any chess move that isn't about the "entire position".

The rules don't care about the "entire position" which is why the description is so short and succinct. There is no reason to mention things that don't matter. The rules only care about the checking (attacking) piece, the enemy king, and the ability to parry the attack. Which is why they don't mention peoples interpretation, like moving pieces, entire positions, "states", or which pieced caused anything or which piece allowed anything.

Just the checking piece, the enemy king, and whether or not the king can escape the attack.

In the diagram above "That move causes the black king to be put in check. It's a terrible move, I know, but it's just an example." That's what a check is. It's an attack. The pawn indeed causes the black king to be put in check. Because ITS the one that's attacking. No different than our other examples where the king is attacked.

Notice the rules about check and checkmate say absolutely nothing about any piece that's not attacking the enemy king.

Yes they do, as with no pieces other than the piece attacking the king, checkmate would be almost impossible. There needs to be pieces that "help" in the checkmate by covering flight squares. And yes, checkmate is an entire position, because here, without knowing the a5 square (Just ONE of the 64 squares), you would assume this position is checkmate

When it turns out the position is this

Take my word for it, he will never get it. The bottom line is this. If you legitimize the sentence the bishop captures the queen, then you must also legitimize the king checkmates the king. On a semantic and reality level they are identical. A "checkmated king" and a "captured queen" are simply features of a changed state attributed to a single piece move. And even on the effect level these two actions are very similar (though that is non-essential). One disables the queen permanently, the other one does the same to the opponent's king.

Were you to apply the same presumed expression rules to the bishop as to the king, you could only formulate the queen capture in 2 ways: (a) the player captures the queen (b) the move Bxd6 captures the queen. That is nonsense since everyone uses the 3rd version (c) the bishop captures the queen. Which consequently applies to the king for all the states it moves into. No choice though many chess articles skip it thoughtlessly. Here is a link which does better. It acknowledges the exception of the discovered check to the "king cannot check(mate) king" assumption. Of course it is not an exception, it is simply a rule to permit discovered check by the king but it is scarce in chess games which is why it is often overlooked in chess texts.

https://chessforsharks.com/can-a-king-check-another-king-in-chess/

When you say "yes they do" what are you referring to? I still don't see what the point of an "entire position" is. Every move is about the entire position, check and checkmate are no different.

If the rules say something about check being delivered by the piece that moves, I would like to see it. All I've read is where they mention the piece that attacks the enemy kings square, not the piece that moved. What rule says checkmate must be given by the piece that moves?

Common sense, as the piece that moves causes checkmate, and therefore, gives the position of checkmate to the board, the game.

You mean your own personal interpretation. Common sense actually says the piece that checks causes checkmate. Because both common sense, and the rules, recognize that checkmate comes from the piece that attacks the enemy kings square. Not the piece that moved out of the way.

Remember the yellow car.

Again, what rule says checkmate must be delivered by the piece that moves? I've never even seen a checkmate rule that talks about either "entire position" OR a piece that moves. The only checkmate rule I've seen talks about attacking the enemy kings square, which can only be the piece that checks.

And every checkmate rule that you've seen describes the position of checkmate, not the action of a piece that checkmates. Checkmate is a position, you need to know all - or at least, most - of the 64 squares in order to determine checkmate. Any piece that moves causes the position to change. Therefore, the piece that moves and causes the position to change into a checkmate position, causes the checkmate. So it's only logical that that's the checkmating piece. I'll provide a diagram to help you understand.

The king's movement changes the position, just like any other move would, as a change in position is actually the definition of a move, in case you didn't know. The main difference here is that the position changes into a checkmate position. So, the king changed the position into a checkmate position; in other words, the king caused the checkmate, by moving. The definition of the verb checkmate is to cause checkmate. Therefore, the king checkmated.

This does seem to be an interminable argument.

Of course, in the absence of a definition of "the piece that causes checkmate" by a recognised body, anybody can, like Humpty Dumpty, have their own personal interpretation.

But it's definitely not common sense to say that the piece that checks causes checkmate.

Checkmate is a situation where the king of the player to move is in check and the player has no legal move. There's no sensible reason to restrict consideration only to the fact that the king is in check. On your basis one might just as well say that the checkmating piece in the following diagram is the Black pawn on d2, because that piece is causing Black to have no legal move.

Of course you could choose any piece other than the Black king, so the use of "the" would be questionable, but so is it in your interpretation. Which is the checkmating piece here?

I agree with @KieferSmith and @Arisktotle that the only interpretation that conforms with common sense is "the piece that last moved".

why dis thread so long heahaehhaehahaehhaeaehe

Because some people post junk?

I understand. However, the rules speak of the enemy king under attack. The attack does not come from the piece that moved. The attack comes from the piece that checks.

The rules are silent on defining which piece delivers checkmate, they only speak to the attacking requirement, not HOW a piece came to be the attacking piece. A great example was provided by Keifer. The car that gets out of the way did not cause the collision did it? The car that collided with the other car caused it because it was the car that was going too fast.

It would be hard to find a reasonable (or common sense) interpretation that agrees the entity that gets out of the way is the party responsible.

Sometimes the checkmating piece is the piece that last moved, sometimes it isn't. It depends on if it's attacking the enemy kings square. I try not to insert my own interpretation into the rules, I'm not an arbitrator. I don't think it's a good idea to add things that aren't there, like "the last piece that moved". I just go by what the rules say. And the rules say checkmate is when the enemy kings square is attacked, and the king cannot escape. Only the attacking (checking) piece can do that. A piece that is not attacking the enemy kings square is not mentioned in the rules (there could be a dozen pieces that are not attacking the enemy kings square).

Although the rules imply the attacking piece is the checkmating piece (because it mentions that requirement) there is literally nothing in the rules that imply the last piece that moved is the checkmating piece. Literally nothing. If there is, could you tell me which rule that is?

BTW, in the first diagram the knight is the checkmating piece. Since it is the one attacking the enemy kings square. In the second diagram, the rook and bishop are the checkmating pieces, because they are the ones attacking the enemy kings square.

I was listening to Lars Larson this afternoon and a caller was offering his opinion on the current state of affairs concerning crime and police pursuits. Some jurisdictions have instituted a "no chase" policy. Which means the criminal can commit the crime, run from the police, and the police are required to not pursue the criminal.

The reason is because in some states it is believed the police, not the fleeing criminal, are the cause of the consequential damages. If a fleeing criminal, doing 130 mph crashes into an innocent victim, it is believed the police are at fault, not the fleeing criminal blatantly driving as recklessly as possible to elude police. The thinking goes "if the police did not chase, the criminal would not flee". Which is of course true. But did the police cause, or "deliver" the fatal crash between the fleeing criminal and the innocent bystander, or did the fleeing criminal deliver the collision? The criminal's car was wrecked, the innocent bystander was killed in their crushed car, and the police vehicle was unscathed. Which car (or driver) delivered the fatal collision?

The smallest steps.

To test any story on "delivery"/"production" on validity all you need to do is apply it, not just to checkmate, but to any state in chess like check, stalemate, dead positions, 50-move draw. repetitions and others I mentioned before. As "delivery" is a general concept with respect to accomplishing chess states it is simply insane to provide a definition that only covers checkmates.

This becomes even clearer when you read what the rules say about "delivering"/"producing" states. They attribute them to "the player" and "the move" but not to anything in the state delivered. Those states (such as checkmate or stalemate) conform to their individual definitions. If there was anything inside any state affecting "delivery" the rules would have identified it.

Which leaves the discussion on "delivery" exclusively to the game phase before the delivered states. The rules could of course attribute "delivery" of any state to the complete preceding game - no objection. In a sense they do that when they point at the player (who played the whole game) as deliverer of the succesive states. They narrowed it down when they also attributed it to the last move ("the move that produced the checkmate") before the state was a fact. The question is if it is possible to attribute "delivery" to a chess unit when the rules do not explicit specify it. But actually they do specify it - in relation to "capturing". A piece capturing another piece is simply a piece playing a move that delivers the state where the other piece is gone (captured). Need not even be on the same square (e.p.). Zero difference with checkmate and stalemate as the process is the same. The differences are only in the definition of the states which we have already shown irrelevant for "delivery". And thus, when a checkmating move is played by a king, it can most certainly be called the deliverer of the checkmating move and the checkmating state.

The smallest steps:

1. A checkmate state is produced by a checkmating move (executed by the player)
2. Moves are attributed to precisely one of the moving units
3. When a move is played by a king, it's called a "king's move"
4. Thus a king's move can be a checkmating move
5. Which we express as "king checkmates king", or "king delivers checkmate".

Finally, what has discovered check go to do with it? Nothing! No one will argue that the move Ke4-e5 is not a king's move because another unit gives check. A move is delivered by a moving unit and not by an innocent bystander.

Nobody is questioning which piece moves. The question is which piece checkmates. Nothing in the rules say, or imply, that the moving piece is the checkmating piece. If it is in the rules, which rule is it? But the rules DO say that checkmate must "attack the square the enemy king occupies". Which in our examples the moving piece does not do. Only the checking piece attacks that square, not the moving piece.

So when we say things like "Which we express as "king checkmates king" it can be confusing. A helpful article was provided in post number 334. Like virtually all sources, it says no, it cannot. But it explains why.

https://chessforsharks.com/can-a-king-check-another-king-in-chess/