Illegal Position Contest!

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Typewriter44

I am on the mobile app so i cant post a board but whiteking@ e6 blackking on d8 whitepawn on e7

Typewriter44

 

Typewriter44

I meant this position:

 

cobra91
Typewriter44 wrote:
cobra91 wrote:

Concrete proof is elusive, but think the position below is illegal. If anyone believes they can demonstrate otherwise, please let me know! 

 

@g6 could only get there from this position:    [...]

Try again. Wink



cobra91
Typewriter44 wrote:

Illegal I believe

Nope - it's legal:



cobra91
Typewriter44 wrote:

I am on the mobile app so i cant post a board but whiteking@ e6 blackking on d8 whitepawn on e7

Sounds legal to me:



graysandwich
AussieRookie wrote:

Guess which piece delivered checkmate first.

White can play kxd5 or kxf5

Typewriter44
cobra91 wrote:
Typewriter44 wrote:

I am on the mobile app so i cant post a board but whiteking@ e6 blackking on d8 whitepawn on e7

Sounds legal to me:



I ran out of time but I meant this: 

 

cobra91
Typewriter44 wrote:
cobra91 wrote:
Typewriter44 wrote:

I am on the mobile app so i cant post a board but whiteking@ e6 blackking on d8 whitepawn on e7

Sounds legal to me: 

[game]

I ran out of time but I meant this: 

[diagram]

But that one is legal, as well:



cobra91

I know people are still having trouble with the analysis for the positions in post #358, but I just can't wait any longer to post this little gem:

Typewriter44

UGH


I keep doing that wrong, I mean this: 

Remellion

In #358 the first (with a ton of promoted pieces) is illegal - you know I know why. The bit about barely having enough captures to promote is the first half of the reasoning; the second half is just a basic insight, a one-liner.

The second though... I believe it's barely illegal. 12+12, count captures, [boring details omitted], realise black played axb, bxa, bxc and exf while white played c2xb3, d2xc3, gxh(pawn) and one spare capture. No useless pieces, so we can't retract d2xc3 now; a wBc1 needs to return to unlock the SW cage. What about the NE cage? Let's play with white's spare capture, the only one available.

Try 1: Retract -1. Ke8xB Bf8... yep, we didn't get very far towards anything there. Can't retract -2...exf6 because of wBd8, and -2. exd8=B is impossible since we already used our spare capture.

Try 2: OK, so the cage can't be opened by wK uncapture, and the h6 end is totally stuck too. Maybe we can get another piece with our uncapture to block on f8. Retract -1. ef3xN Nd4 -2. h4 Ne6 -3. Ke8 Nf8 -4. gh4xP h5 -5. Be7 (again can't unpromote) h6 -6. Bd6 ef6xP -7. f5 or Bf4, lo and behold we're just a move short. Drat.

Try 3: That sequence looked promising, but it comes up short. If instead -3. h3 Nf8 -4. ghxP the wPs on e2 and g2 render wBf1 useless, impossible.

Try 4: And if instead -6. Kd8 trying to hide behind the bishop on c8, well black's still stuck anyway.

So I claim illegal. If that's right then it's a nice try sequence you put in there.

Adihere
AChessPlayer2016 wrote:
Typewriter44 wrote:
AChessPlayer2016 wrote:

So illegal.

I don't think so 

 

I forgot to say "Black to move".

Do you mean "White to move"?

Even if you do:-

 

realybadchess
[COMMENT DELETED]
cobra91
Remellion wrote:

In #358 the first (with a ton of promoted pieces) is illegal - you know I know why. The bit about barely having enough captures to promote is the first half of the reasoning; the second half is just a basic insight, a one-liner.

The second though... I believe it's barely illegal. 12+12, count captures, [boring details omitted], realise black played axb, bxa, bxc and exf while white played c2xb3, d2xc3, gxh(pawn) and one spare capture. No useless pieces, so we can't retract d2xc3 now; a wBc1 needs to return to unlock the SW cage. What about the NE cage? Let's play with white's spare capture, the only one available.

Try 1: Retract -1. Ke8xB Bf8... yep, we didn't get very far towards anything there. Can't retract -2...exf6 because of wBd8, and -2. exd8=B is impossible since we already used our spare capture.

Try 2: OK, so the cage can't be opened by wK uncapture, and the h6 end is totally stuck too. Maybe we can get another piece with our uncapture to block on f8. Retract -1. ef3xN Nd4 -2. h4 Ne6 -3. Ke8 Nf8 -4. gh4xP h5 -5. Be7 (again can't unpromote) h6 -6. Bd6 ef6xP -7. f5 or Bf4, lo and behold we're just a move short. Drat.

Try 3: That sequence looked promising, but it comes up short. If instead -3. h3 Nf8 -4. ghxP the wPs on e2 and g2 render wBf1 useless, impossible.

Try 4: And if instead -6. Kd8 trying to hide behind the bishop on c8, well black's still stuck anyway.

So I claim illegal. If that's right then it's a nice try sequence you put in there.

Very good! Smile  Kind of amazing how quickly such positions go from "impossible" to "easy" once an actual problemist arrives on the scene.

As can probably be gathered from the first position, all 7 of the positions I've posted in this thread are based on past compositions of mine, rather than constructed from scratch. Most of the problems they're based on were already posted here: https://www.chess.com/forum/view/more-puzzles/unbelievable-to-me

The above thread is basically extinct at this point (although I do plan to post a few more problems there, since I've already begun working on them and am unlikely to stop until they're complete), which is why I've gradually transferred them (in illegal form) here - this thread has been infinitely more lively! Laughing

graysandwich

 

CheesyPuns

illegal i think

 edit: add a white pawn on h2

now its illegal?

Typewriter44

Legal

Typewriter44
cobra91 wrote:

I know people are still having trouble with the analysis for the positions in post #358, but I just can't wait any longer to post this little gem:

 

@e6 and @a5 can't get there because the only one white piece has been captured is the light squared bishop

cobra91
Typewriter44 wrote:
cobra91 wrote:

I know people are still having trouble with the analysis for the positions in post #358, but I just can't wait any longer to post this little gem:

 

@e6 and @a5 can't get there because the only one white piece has been captured is the light squared bishop

Count again. I'm pretty sure White is missing more than one piece.