AMAZING Chess Puzzle From Reddit

[@nickcellino1503]

I've seen thousands of chess puzzles but this one may be the most amazing of all. Nelson's perfect commentary enhances the beauty of the composition.

[@gabydewilde]

I cant remember ever seeing one that I just couldn't solve. It reminds me of what magnus said about cheating when asked what he would need to cheat. Just a single signal one time in the match would be enough. It would be to indicate a complicated winning move is available. Then you simply find the move. In other words, chess puzzles are cheating :P

[@JohnDoe-ti2np]

In 1995, John Nunn shortened a study by Matous to produce this position, as an engine-stumper. It's interesting that it continues to stump engines today, almost 30 years later.

[@janbilek367]

The engine solves the study in seconds (mate in 12).

[@cowvintube]

@@janbilek367 I tested this position with Lc0 on my PC and it took 1 minute, but my hardware isn't the fastest.

[@Autrone]

Really crazy how Stockfish does not focus on "wayward" moves (like the move that it does not detect) but rather "direct" moves that are straight to the point but creates a draw in this instance! This is for Stockfish to be resourceful on memory by eliminating "wayward" moves that have less chance to generate a win and giving more depth to the moves that seem more "winning". Good to see you back after disappearing from my recommendations for 3+ years! Time flies so fast!

[@luckydust4375]

Yeah there is still some flaws with Stockfish there Maybe it would need to stop calculating drawing lines further and further when it's obviously a draw to focus on analysing previously discarded moves Like "ok this is a draw, now do I have a better option?" Especially when it have infinite time to think

[@Rocky64]

Contrary to what the video claimed, Stockfish actually finds the long forced-mate instantly. Chess Vibes keeps using the bad default Chesscom setting that limits Stockfish's depth to 22 - an artificial handicap that weakens the engine considerably.

[@tuxedobob2]

@@Rocky64 Does a depth of 22 count both white and black moves toward the depth? If that's the case, I feel like it shouldn't find forced mate in anything above M11, but it does, doesn't it? It's more likely that moving the bishop is a "weird" move that Stockfish discards early on.

[@jameswang7362]

No, Stockfish (and Komodo) run alpha-beta searches, which evaluate the position for every possible (winning) move. It has nothing to do with intuition. If there is a mate in 12 and you let it search up to 24 ply Stockfish WILL find it - it's mathematically guaranteed. The depth was just artificially handicapped to 22 ply in this puzzle. You could say the same about a Stockfish limited to 1 ply and entirely relying on its NNUE heuristic.

[@jameswang7362]

​@@tuxedobob2Yes, 22 is the depth of the game tree, which gets one level deeper for each player move. So 22 deep detects all mates in 11 and below. In these positions Stockfish can easily get to 35 or so depth if you don't just cut it off.

[@wickedpawn5437]

This is perhaps the most insane puzzle I've ever seen.

[@Grayback1973]

Until you see the next "most insane" one you've ever seen.....lol

[@Emily-xl8qw]

​@@Grayback1973do you also call your girlfriend "the best person in your life until you meet a better one"?

[@unrenownedc]

​@@Emily-xl8qw awful comparison

[@Emily-xl8qw]

@@unrenownedc skill issue

[@unrenownedc]

@@Emily-xl8qw that's your life

[@Phixersor]

Me, a 900 rated player, after hearing stockfish see no win, still pauses to have a look.

[@golux-57]

There's another interesting line where white has to be very careful -- if, when the queen and knight are keeping the white king from moving black can play Nd5+, and if white moves anywhere except Ke6, Nc3 blocks the bishop *and* delivers a check on white's king. Black can then perpetually check until a 3-fold draw is reached.

[@johnathanpatrick6118]

2:30 -- Cue Eric Rosen: gxf7+, a pin and a fork, a pork!! 🤣🤣

[@luqmaanhay4957]

Also from Gauri chess

[@JustAnotherCommenter]

@damyankuzmic5605That's not how you spell "lol". Do you live inside a cave or something?

[@PostWin]

@damyankuzmic5605 Lol means Laugh out loud, as in you are laughing audibly

[@PostWin]

@damyankuzmic5605 1. It does make more sense, I can tell English isnt your first language so Im not trying to insult you. But laughing out loud is coherent and means something while laughing on loud doesnt make any sense. 2. It doesnt matter if it would make more sense(it doesnt) because even if it does, the acronym is still laugh out loud. You can look it up, you dont change acronyms even if you think another word to replace it makes more sense.

[@PostWin]

@damyankuzmic5605 There is almost no time an outsiders perspectives will be right in terms of changing the language. It doesnt matter what you or I think, LOL is an acronym that means laugh out loud. It doesnt mean laugh on loud, it will never change from laugh out loud even if you think it doesnt make sense. It will be like me saying The Leaning Tower of Pisa looks more like a pillar so I will call it The Leaning Pillar of Pisa, I am just wrong because that isnt what it is called even if I think it fits more. Probably also shouldnt be thinking you know more about the English language just because you think one sounds better than the other, instead you should understand why this is right even if it sounds wrong. Otherwise implementing your own rules would make you illiterate to everyone else.

[@harikumars1487]

This is THE best chess puzzle I've ever seen 🤩🤩 Thank you very Nelson for bringing this up!

Mario Mattous was the composer... he made a lot of problems like this one

[@gabydewilde]

A real problem maker

[@cougar2013]

I wish wish wish wish wish that Nelson would run through the full puzzle once quickly at the end of the video, just so we can see the wonderful solution in full motion. Love the channel!!

[@doglover31418]

You could watch it again at x2 speed in 'settings'

[@RushikeshSahasrabudhe]

@10:00 ...What if black queen moves to f8 to prevent check from white bishop?

[@FuturePast2019]

KE6 and KE7 and the pawn...

[@wayneyadams]

This is a phenomenal puzzle, and I would never have figured it out within the time constraints of an actual game. I'm not even sure I could have firgured it out given unlimited time. Thanks for showing this to us, especially the part about delivering the checkmate by moving the King.

[@giovannitomasoni7990]

At 10:10 i was wondering is black play Qf8; kf5+, Qg7; Bg7+,Kxg7; and it’s a draw. What i’m missing?

[@giovannitomasoni7990]

Ok, i understood what i was missing, after Qg7; f8=Q#

[@r6u356une56ney]

At 9:44 - consider if black moves queen to A3. Covers both the bishop and the promotion at f8... edit: Ok, if so, you move king, check, but queen takes bishop. You can *then* promote the pawn for mate...

[@WithOneS]

Queen to F8 at the end is an interesting position I wish you could’ve explored!

[@Alanchess]

Qf8 fails to Kf5+ Qg7 f8=Q mate!

[@WithOneS]

@ saw that after the fact, but still a complex position that I wish was covered!

[@Jo24Park]

2:58 What I struggle with in this position is that the black queen does not need to move away from its square in response to Qxc7. There are pawns to move towards promotion. So in this case white's queen cannot return to a8-d8 (or the diagonal guarded by black's queen) or it will simply be taken by black's queen and the white pawn will never have a chance of being promoted. When black moves their pawns, would the white queen just follow and capture them until white's queen ends up on the right hand side of the board to deliver checkmate from there?

[@Ozasuke]

One of the coolest puzzles I have ever seen! Thank you for sharing and breaking this down!

[@simens8646]

At 10:00 you are going through many of black's variations, but there is one important variation that you don't show. Black could play Qf8 intending both to block promotion and also to block the white bishop with Qg7 if the king moves. This also loses, but in a slightly different way than other moves. White doesn't capture the pinned queen on g7, but simply delivers mates by promoting on f8.

[@msolec2000]

Yes. A check and a pin. A chin.

[@JohnTVian]

This is a very interesting puzzle. One way it could have gone is 1. Bc7 Qxc8 2. gxf7+ Kh8 3. Be5 Qc5 4. Bb2 Nc7 (This freezes the white king from going anywhere but black is zugzwang.) 5. Ba1 a4 6. Bb2 a3 7. Ba1 a2 8. Bb2 a1= (Any piece will do.) 9. Bxa1 Qc3+ 10. Bxc3 Nd5+ 11. Kf5+ Nf6 12 f8=Q# Another alternative

[@midnighttrain-jz2my]

I like how Stockfish suddenly realizes: "Oh yeah!... there is a checkmate there" 😅So sad, poor Stockfish cant talk to us, he would have so much to say.

[@arifbagusprakoso2308]

Well, the stockfish depth is only 22. That means it can only find M11 at max. The puzzle is M12. Change depth setting and you'll see stockfish true power.

[@tandrimadasgupta1222]

2:09 stockfish suddenly gets smart 🤓🤓🤓😂😂😂

[@reubenmanzo2054]

To answer the question at 4:52, I once checkmated by castling.

[@Fronzel41]

Elaborate

[@reubenmanzo2054]

@@Fronzel41 I castled and where the rook was positioned lined up with the enemy king and it was checkmate.

[@starman8086]

I believe I have as well...

[@luckydust4375]

Try analysing positions with Stockfish 16 instead of Stockfish 16 lite. The lite version is often a bit off. Stockfish 16 will find this mate before reaching depth 30. It's always frustrating to me to hear "Stockfish can't find it" and see "Stockfish 16 lite depth 22" in the corner. Amazing puzzle btw

[@thomasr2472]

I tried with Stockfish 16 up to depth >50, it does not work. Note that if you show Stockfish the solution, and then undo and analyze the same position as before, it will indeed find the right move! This is because it caches previous results.

[@luckydust4375]

@@thomasr2472 Yes that's why I got it to find it at depth 30 Still, if I have to check by myself to make sure that the true Stockfish doesn't find it it's a bit annoying. If you want to say that Stockfish doesn't find it, fine, but show us the true Stockfish and without the depth cap otherwise what you show is useless cause unrelated to what you say

[@anonym5160]

I let the puzzle analyse with Stockfish 15.1 and he can‘t find the winning move doesn‘t matter how long it think.

[@luckydust4375]

@@anonym5160 doesn't change my point. Sometimes Stockfish 16 lite will miss what Stockfish 16 would find. Therefore, everytime you Say "Stockfish doesn't see it" with an image of Stockfish 16 lite not finding it, what you show is unrelated with what you're saying. He should show us the Real Stockfish 16 no depth cap analysis, that would really illustrate his comments.

[@blacktigershearthstoneadve6905]

@@thomasr2472 Not sure how you tested it. I just tried it with Stockfish 16, depth 32 and it found the solution... not immediately, but failry quick.

[@windowsmoke]

This is not "from reddit" please credit the original composer when showcasing studies, this one is by Mario Matous from 1975. Also it is missing a move, being (with the white queen on a6 and the black king on f8) Qc8 Kg8, reaching the position showcased here

[@JohnDoe-ti2np]

Yes. In 1995, John Nunn shortened Matous's study to create a puzzle for a Batsford Chess Competition. Nunn specifically selected this position (and two others) to be difficult for computers.

[@BlckJack123]

Hats off to whoever developed this puzzle! Can you imagine how much effort had to go into figuring something like this out?

[@seanberquist106]

At 7:07 why not black queen to F2 check? The check again prevents pawn advance, and the queen can take the bishop if the king moves to expose the pin. Thanks for sharing a great puzzle.

[@wickedpawn5437]

Qf2+ Ke6+ Qxb2 f8=Q++

[@epichunter3488]

​@@wickedpawn5437ke6 ? Sacrificing the king😂😂

[@DonaldRoy-nr9xe]

5:11 move queen to f8. There is options after this to checkmate white.

[@sagov9]

Qf8 Ke6+ Qg7 f8=Q# the queen will be pinned by the bishop so not defending the promotion square

[@MartinHain-ls9sc]

what happens if black moves QB3+ (check + bishop threat)?

[@paulblum2204]

What happens if queen back king.moves and queen blocks

[@roguebarbarian9133]

Not only did I checkmate with a king once, I checkmated by moving out of an opponent’s check.

[@ounalan]

I suggest you should have continued analyzing. In the last position after Bxa1 if Qf8, Kf5+! Qg7, f8=R/Q+ and mate.

[@justinjja2]

Thanks, saw that and was thinking bishop takes queen is just losing. Didn’t realize you just promote.

[@christopherlperezcruz1507]

Damn I saw the same thing forgot they don't have to take. Can you imagine playing Magnus and when you sac your queen, Magnus just concedes cuz he figured the rest out!?

[@wesleydeng71]

He also missed Qf8 in previous positions, so.

[@ericvangent1302]

I wanted to react , then I saw you came up with the same as me. Beautiful, isn't it! 😂

[@dmitripogosian5084]

@@wesleydeng71 That was not critical, indeed, on some moves from zhugzwang, you just promote with a mate, rather than move your king

[@codingvibes3537]

what about qa3 at 10:54??? Please someone answer this fast...I am getting very annoyed

[@Adammarshall2341]

After the bishop capture you can just promote to a queen with mate

[@codingvibes3537]

@@Adammarshall2341 oh yeah...thanks for the answer

[@astro_ash]

5:56 what about q f2

[@scion.]

Same, king moves and bishop delivers discovered check. After Qxb2 promote the pawn

[@andrekotz7803]

10:48 what if black pushed the pawn?

[@Together4.4M]

You’d just play Kg6 and it would be mate

[@coolpapabell22]

Challenge idea: Beat Martin but your last move has to be moving your king. :)

[@avinashbharti4366]

5:53 queen f2 is a fork. Am I missing something?

[@Bootymuncher42069]

If qf2 ke7 check then white promoting the pawn is unstoppable

[@userac-xpg]

Chess was so much better before engines. Now every 1200 player acts like they know every solution

[@singularityphoenixx]

The internet was so much better before eternal September. Now every poster is a bot or troll.

[@userac-xpg]

@@1happystone166 puzzles like this have been created for hundreds of years.

[@Puschit1]

Everything was better back in the day, ask your grandparents. Or wait, are we now the grandparents?

[@SomaChatterjee-kd6hd]

I saw this puzzle in gauri chess before....

[@davidjames149]

i knew i'd seen before it but couldn't remember where, Gauri is an absolute legend

[@eemihelisten3137]

@damyankuzmic5605 This is an invented puzzle

[@honestloz]

Brilliant 👏 👏

[@andrewgoldfarb3431]

I saw this it last week on puzzles engine can’t solve

[@avijatsinharoy8944]

Same here

[@FirstLast-is9xe]

Why does Stockfish not see that? I tried depth 42 and still thinks this is an equal position. This may be key to make Stockfish better! It disregards some crucial moves, instead of trying them

[@Amro-h7x]

Bishop B2 is the only winning move because black can push the pawn and you can position the bishop between a1 and b2 without being attacked. If bishop goes to a1 you will get attacked by the pawn and black can deflect the bishop

[@davidhein4725]

I thought of something, have no idea if this idea would work or not, @10:00 in the video, if it's blacks turn, why doesn't queen to f8 work? King would have to go to 5th rank, then maybe g7 for queen? I have no idea if that would work, I am no pro at chess by any means.

[@fep_ptcp883]

After black queen blocks in g7, f8 promotes to queen or rook and delivers checkmate

[@ChessInstructorSF]

Nelson, yes mind tweeting but what about from the last position if Qf8 King moves Bishop delivering check Q g7 interpose, Bishop takes Queen check, King Takes Bishop King controls f8 so any promotion will be captured??? Look into it please! Thanks in advance. Ah after looking at it further, I realized that after Qg7 the Queen is pinned and f8 = Q or R mate!!! Now I see it… Wow in deed!

[@adityachk2002]

The power of Reddit and communities.

[@QDWhite]

I love how stockfish offers the draw and then afterwards is all like, “of course this is winning for white. Wasn’t it obvious?”

[@happydays334]

It never did it always said mate in 2

[@suchapinch7481]

At 5:22 king e6 and white is going to promote after e7. What am I missing?

[@zsombororovec645]

10:57 the position looks cool after Qf8, the only winning move is Kf5+, because the Qg7 is not check and then White must promote to a queen or even coller: a rook. Thanks for the video it was really mindblowing.

[@terencemah8521]

I believe white Kg5+ is still winning, unless I'm missing something. After Black plays Qg7+, White plays Kf5 and Black can no longer stop f8=Q#, even if queen takes bishop, since the queen is pinned on the diagonal and can't deal with the pawn. If Black plays Ne6, covering the f8 square, then the king simply captures the knight.

[@zsombororovec645]

​@@terencemah8521Yes, you're right, Kg5 also works, and you just have to go with the King to a square that the night cannot check you on, so Kh5 or even Kh4 are good as well. Thanks for the correction.

[@jurijpuc5752]

When you moved the bishop on A2 couldn't it be countered with queen F2, checks the white plus takes the bishop!

[@alrees61]

pawn on g6 takes pawn on h7 check. king takes pawn Qneen to H3 check King to g8 Queen to g4 check King to h8 check Queen to G7 checkmate

[@marcelodelpuerto395]

After white moves bishop to b2, why doesn't black fork the bishop with a check at c3 then even if white promotes the pawn, they can take the new queen and then promote black pawn at row a.

[@andyF1K]

What am i missing? Queen to f8 Black moves king, quueen g7, white takes with bishop, black takes with king white does whatever, black taks pawn...im missing something.

[@chbrown]

After the final zugzwang, when the Q or the N have to move, there's one last mind-blowing variation, which is Qf8, looking to block the bishop's check, let's say White plays Kf5+, then Qg7 blocking the bishop's check... but at the same time the Q's pinning herself so f8Q boom! beautiful mate.

[@Zlittlepenguin]

I’m just a lowly 900, but why at 10:30 would Queen g8 not work as a move? Edit: nvm I ran it myself lol. If anyone else is curious, white can just promote the pawn after the queen blocks which is checkmate since the queen is now pinned.

[@w3g619]

9:55 What about Qf8? White king moves, but black queen can block the check with Qg7.

[@Grimlock1979]

Then white promotes the pawn. Black Q is then pinned, so it's checkmate.

[@fep_ptcp883]

Then f8=Q#

[@rajeshv9549]

Amazing puzzzle! In the starting position, if the pawn is in a7 instead of a5, it is instead a win for BLACK with the same incredible variations. Regardless of whether the bishop goes to b2 or a1, black can corresponding move the pawn from a7 to a5 or a6 (correspondingly) to eventually put black in zugzwang!! The option of moving 2 squares or 1 from a7 gives that wiggleroom!! A truly outstanding puzzle, well explained by Nelson!! btw, if someone has already posted this, apologies (didn't read through all the 100s of comments)!

[@DonaldRoy-nr9xe]

7:48 again queen to f8 leads checkmate options for black.

[@Klatubarada1979]

No. Kf5#

[@shepaluteprez]

Wait! What happens in that final move if the Queen moves in front of the white pawn? King moves, Queen can block the bishop. Black would win. This is a move you did not explore.

[@fep_ptcp883]

No. Queen would block the bishop check, but then white pushes the pawn and promote to queen. Checkmate, the black queen is pinned by the bishop

[@christopherlperezcruz1507]

Why doesn't black move Q to f8? When the K moves for the check he has to move away from the pawn. The Q steps in and sacs but the king can retake and move to f8

[@dormitivevirtue]

If queen blocks bishop doesn't have to take it. White promotes the pawn then its checkmate because the queen is pinned.

[@petersiegfriedkrug]

But this endgame study by Mario Matous is world famous. All really good chessplayer should know this chess study. Matous died in 2013.

[@Aut0KAD]

it also confuses stockfish in the beginning which is incredible

[@happydays334]

Nope it's sees mate in 2 it was fake

[@MtisungeNyirongo]

There's no way am solving this puzzle in my entire life. Thanks for sharing Nelson

[@starman8086]

I've only checkmated by moving my king once in my entire chess career.

[@pnachtwey]

I plugged this puzzle into Stockfish 16, It took it 92 plies and a few hours to solve. Stockfish had to look past a lot of forced moves find the solution. I was using a AMD 3.3Ghz 32 GB CPU on stockfish 16 with Arena UI.

[@joshualemmon5806]

4:53 I have. I've even delivered checkmate by castling.

[@fraer111]

I saw this 'checkmate battery' at once, but it's really OUT OF THIS WORLD Incredible!

[@Grayback1973]

Brilliant puzzle, wow. It just seems that the amount of chess puzzle possibilities is infinite!

[@osgubben]

This is the only puzzle I have saved on my hard disc for years, since no comps could find the solution for me. Still the most impressive and hard puzzle I have seen. What a genius puzzle!!

[@minzhang1413]

Can you do a video of the hector gambit?

[@fuglbird]

I've played chess since 1966. It's common courtesy to refer to the composer of a study when you present it. You don't just write "local newspaper", " a bloke in the pub", "reddit" or something like that. This study was originally presented by Mário Matouš in Szachy 1975. You are showing a shortened version, where the first moves by white and black have already been played.

[@MichaelBaker-k5x]

White pawn takes blacks pawn on h7 for check. Blacks king takes the pawn. Now white moves its queen to h3 for check! King goes to G8, queen to G3 check and mate next move! It is 100 times easier!

[@MisterHand1]

...Kh8 instead of taking the pawn.

[@kukytranza9922]

Best lines for black after Bxa1 are either ...Qc3+ or ...Nd5+ (delays mate the most)

[@giannisnikitakis4983]

Would magnus Carlsen see bishop c7?

[@dVTHoR]

Certainly the greatest puzzle I’ve ever seen

[@Blablablabla1ify]

When you first move bishop to b2, what’s stopping queen to f2 check, then take the bishop?

[@voidmarvin]

First time you would see Kxy#

[@divVerent]

Yeah. I once pulled odd a 0-0-0!! winning a bishop and thereby the game, but a king move for checkmate is something else.

[@DanielPhillips-ny5sf]

Black queen to F8 at the 10:30 mark kills this.

[@studytable2060]

king to f5,queen blocks at g7 and white gets a queen delivers a checkmate, as black queen will be pinned from bishop

[@starman8086]

@@studytable2060 Yes that's right...

[@screamer22222]

What about black queen to f8 as last move? So when the bishop does checl the queen can interrupt the check, no?

[@ДенисЗайцев-д7б]

A human can guess the first idea and the first move. But the full picture is much, much more beautiful. BTW, 1. Bxa5 and 1. Bb6 are the moves worth some analysis.

[@iberianoutsider3287]

Este puzzle lo pusieron en un foro de amigos y la verdad es que, ahora que veo el estudio al detalle, es una pasada. Sin palabras me quedo 🤐😳

[@pakasokoste]

This is a well known study, not a puzzle, by Matous. Very difficult and fascinating study.

[@yyyy-uv3po]

I feel like I've just watched a 2 hours action movie. Very unique puzzle.

[@jeythegrey]

Imagine getting this in puzzle rush

[@Tassaczek]

Stockfish does not calculate all moves. He chooses a few and checks them. So an algorithm for choosing candidate moves has some problems :D

[@chloesmith4065]

This is one of if not the best and craziest chess puzzle I've ever seen.

[@SagarVishwanath]

What happens if black checks with f2 and take the bishop?

[@LuizHenrique-qo9xp]

I don't see this option. If it was before knight preventing king to e6. After that bishop will be at a1. Before the knight movement king to e6 is checkmate.

[@Thebeautyofediting]

​​I DONT KNOW WHY BUT I LOVE THE HIYORI MOMENT BECAUSE IF A JUGEMENT HAPPENS TO THE CELESTIAL DRAGON, SHE WOULD BE A GREAT COUNTER ARGUMENT TO SOMEONE LIKE MAYBE VIVI WHO WILL FORGIVE THEM. DONT FORGET THAT ODA WRITE IN LONG TERM SO MAYBE THAT WOULD PLAY A ROLE LATER, I'M PRETTY SURE

[@virtualanupom1174]

This puzzle is already Shawn on many channels

[@ppmendonca1]

From the last position both knight to g8 and queen to f8 prolong the defence...

[@ifer1280]

That moment when the king was in a mating net with barely any adjacent pieces, preventing him from delivering checkmate, was magnificent

[@yellowphoenix9803]

Nelson, this is one of the most popular puzzles ever. I know the solution before watching the video since I have and many others have seen it

[@TheEthikos]

This puzzle is absolutely beautiful.

[@goku_naruto_rubber]

Well, in the end, when white captures the pawn in a1, black still can avoid a humiliating checkmate by the white moving his king, by 1) sacrificing the queen in e5, bishop takes, Ne8 check, fxe8=Q checkmate 2) directly go with Ne8 check, fxe8=Q check, Qf8, Qxf8 checkmate. And the second case is also a nice trick for black, because if white doesn't capture the knight directly with the pawn, but still want to checkmate by moving the king to e6, then Ng7 with check, BxNg7, KxBg7 and black now has a winning position since white cannot promote to f8.

[@kzkaa.]

This doesn't stop checkmate, but it does stop a humilating one.

[@robheusd]

A queen move to a3 or g1 or a knight move to e8 can procrast the checkmate but not stop it. But knight to d5 with check will stop white from winning because after the white king moves with discovered check, knight to c3 blocks the bishop. Bishop can not take it because the queen defends it and the promotion square is also defended by the queen.

[@sagov9]

@@robheusd so the queen is overworked. take the knight anyway and after the queen recaptures she is no longer defending the promotion square

[@wagrimm]

So with the bishop in A1 with black "unable" to move, what if the night moves to check the king? then the king moves, knight blocks the check. OR, black moves queen to G1, king moves, queen takes bishop? There's ways out

[@gumby6894]

Your wrong black moves his other pawn while the king is in the line of the bishop😢

[@FuturePast2019]

KG6 mate

[@saifulimam1631]

In the end, it could be explained if Black moves their Queen to f8

[@TomBarrister]

Stockfish also finds the move if you expand the search until Bc7 comes onto the analysis screen as one of the candidates.

[@christopherheckman7957]

2:14 If Stockfish can see a mate in 11 from the position after White's move, then why can't it see a mate in 12 from the original position? 7:56 and now I think I see why Ba1 at first loses; it's because of a parity condition (due to Black pushing the a-pawn). Holy **** this is a good one. 8:56 Well, Black doesn't HAVE to promote to a queen ... but it doesn't make a difference. 10:10 Hats off should be even more so to the composer (who has been identified in another comment).

[@RandyRanson-d5x]

Beautiful use of the chessboard.

[@dovahkiin2259]

I would have lost, thought that Ba1 was the winning move. Totally misded the knight move trapping the king. Wonderful puzzle.

[@mathewsamuel1386]

You're a chess genius, sir!

[@gabydewilde]

Funny, after the bishop move reveal the erroneous "but my king is in de way" thought vanished.

[@ytmndman]

I actually saw the Bc7 idea (I tried Be7 first but quickly saw that it didn't work) but I didn't find the whole solution.