The Puzzle That Hurt My Brain

[@ravi12346]

11:35 Be2 works, but Bb7 seems a bit more straightforward.

[@shanks4u]

Thank you, i was losing my mind wondering why this wasn't the solution and was wondering if i was missing something

[@RS-handle]

had same thought

[@frfancha]

Yes exactly and that pretty much removes the "mind boggling" effect so no sure this is the best video of this channel - which stays my preferred chess channel though . Unless we all miss something??

[@kirillzakharov7336]

Be2 also works right away instead of Bf3. Leads to the same position.

[@MaskOfCinder]

Yes I thought this as well.

[@witheringhs7766]

12:14 isn't bishop to b7 just straight up better and forces the same outcome except without losing a piece?

[@malharmanagoli]

This is a puzzle where knowing theoretical endgames is helpful. The point is that (after pushing the pawn to c7) 1. White can only win by getting the king to b8 where it controls two squares on the short c8-a6 diagonal, and 2. As soon as the black king attacks the pawn, white king has to stay defending it and can no longer move. With this in mind, the moves make a lot more sense. 2 c7 must be played to prevent Kc4. 3 Ke3 instead of Ke4 to not walk into a check, making sure Kc4 is prevented due to the skewer threat 4 Be2 gaining a tempo on the black bishop into 5Kd4 is the only way to prevent the black King from reaching b6. After this point the video explains the logic pretty well. I had learned the bishop and pawn vs bishop endgame from an old video by chessexplained, though I must admit I did not remember what I learned and needed a refresher. Thanks for all the cool puzzles you keep posting.

[@LexxKD]

Thanks. You are right. Let me add a little clarification to your comment. The riddle is really about the endgame of same-square bishops and pawn. In the classic version, the white pawn stands on b7, and the black bishop walks along the trajectory a7-b8-h2-g1. To win, White needs to drive him away. To do this, the white bishop occupies square b8, and the king defends it. The black bishop is forced to move to the a7-g1 diagonal. Next, the white bishop moves to h2, black, in order to contain the pawn, is forced to occupy square a7. White moves the bishop to g1 after which Black resigns, since square b8 is protected by the king and there is no longer any way to prevent the pawn from becoming a queen. In the riddle, the situation is the same, only the black bishop dances around a6-c8-h3-f1, which complicates the situation. In order to drive him away from the white pawn, we need to build the same trap as in the endgame and this is the only chance for white to win. To do this, the white king needs to take control of the b7 and c8 squares and move the white bishop along the c8-h3-f1 squares. And how to do this is perfectly described in the comment by malharmanagoli and shown in the video.

[@martinmelhus7324]

At 11:30 in the video, Nelson goes on to say that B-e2 is the winning move, and I can see why that wins. But what about B-b7? I don't see a line for black that wins or draws from that move.

[@mangopie7602]

Tried it and it works, there's nothing fishy about Bb7 and it's more straightforward

[@AgainstMyBetterJudgement]

I think Nelson just got tired of trying understand why 5000 different variations didn't work and just gave up.

[@AutPen38]

Bb7 is best. It's probably only hard to see if your brain has been broken by looking at all the other variations. From the comfort of our homes, it looks "obvious" and I believe it's what the engines pick, because it literally leads to a faster checkmate.

[@dmaster20ify]

@@AgainstMyBetterJudgement Seems as if Mr. Nelson, with all due respects may need to sharpen up on his endgames.

[@92PedroBorges]

1:40 what prevents black to play bishop e2 check? That would force the white king to move and sacrifice the bishop. Then it’s easy for black to capture the pawn. I haven’t thought many steps beyond it, but it seems to me that the only way to win would be to start preventing that.

[@andydaniel3070]

I think any human plays Bb7 at 11:35, not Be2. It still guarantees the pawn promotes, but doesn't sacrifice the bishop.

[@Aarush.A.S]

Ya

[@LeoKinhg]

Be2 was the first thing that came to my mind, since the bishop doesn't have anywhere else to go. But be7 looks better fr

[@92PedroBorges]

0:45 but if you do that, what prevents black to play bishop e2 check, forcing white to lose their bishop? Shouldn’t that be the first thing to take care of?

[@AlpControl]

@11:30 Bb7 is a better move because it doesn't loose the bishop. Fascinating anyway, thank you.

[@Hordil]

Bishop b7 Gang rise up

[@farouqbaiti4315]

11:44 If Be2 works,then Bb7 also works. I thought that puzzle was simple,but it was complicated and cool and fun.

[@AutPen38]

I think Bb7 is not just "more obvious" to someone with eyes in their head, it's actually the tablebase engine move because it leads to the quickest promotion and checkmate.

[@ThomasHDBass]

One important factor you did not mention was that white wants to force the black bishop onto the short diagonal. Actually, white needs to do this two times. The reason behind this is that the diagonal a6-c8 has only 3 squares. White can cover 1 with the bishop, and 2 with the king. If the diagonal had only 1 more square, we could not force the bishop out. First, the early c7 forces Ba6, which places the bishop on the less flexible diagonal compared to c8-h3. When the white king lands on c6, the black bishop can be forced to let the king in on the side the black king is, so the black king can't intervene. And once the King is on b8, covering two of the three squares of the a6-c8 diagonal, we can push the bishop around, until it is back on the short diagonal, where it only has one square, which our bishop can easily take away.

[@CrazyLinguiniLegs]

4:16 “The only winning move is Ke3” but I beat the engine with Ke4. I was able to get (and keep) my queen on move 39. Here’s how it went: 1. c6 Kc3 2. c7 Ba6 3. Ke4 Kb4 4. Be2 Bb7+ 5. Kd4 Bc8 6. Kd5 Bh3 7. Kc6 Ka5 8. Kb7 Be6 and I figured I pretty much had it after that (which proved to be correct). So, I got my queen on move 39, but once I realized what I had to do, I was able to play it again and get my queen on move 17.

[@kirito3082]

3. Ke4 Kb4 is already the wrong response from black, the correct is Bb7, and the engine does find that so I don't know which engine you're using

[@CrazyLinguiniLegs]

@@kirito3082 What about this? 1. Ke4 Bb7+ 2. Ke5 Kb4 3. Kd6 Kb5 4. Bg4 Kb6 5. Kd7 Kb5 6. Be2+ Kc5 7. Bg4 Ba6 8. Be2 Bb7 9. Bf3 Ba6 10. Be4 Kb6 11. Bd5 Kc5 12. Be4 Kb6 13. Bd5 Kb5 14. Be6 Kc5 15. Bh3 Kb6 16. Kd8 Kc5 17. Kd7 Kb6 18. Bg2 Kc5 19. Bf1 Bb7 20. Be2 Kb6 21. Bg4 Kc5 22. Be2 Kb6 23. Bc4 Kc5 24. Be6 Ba6 25. Bf5 Bb7 26. Be4 Ba6 27. Ba8 Bb5+ 28. Kc8 Bf1 29. Kb8 Bh3 30. Bb7 Bf5 31. Bc8 Bd3 32. Bh3 Ba6 33. Bf1 Bxf1 34. c8=Q+ Kd4 … and from there, white wins.

[@CrazyLinguiniLegs]

@@kirito3082 What about this: 1. Ke4 Bb7+ 2. Ke5 Kb4 3. Kd6 Kb5 4. Bg4 Kb6 5. Kd7 Kb5 6. Be2+ Kc5 7. Bg4 Ba6 8. Be2 Bb7 9. Bf3 Ba6 10. Be4 Kb6 11. Bd5 Kc5 12. Be4 Kb6 13. Bd5 Kb5 14. Be6 Kc5 15. Bh3 Kb6 16. Kd8 Kc5 17. Kd7 Kb6 18. Bg2 Kc5 19. Bf1 Bb7 20. Be2 Kb6 21. Bg4 Kc5 22. Be2 Kb6 23. Bc4 Kc5 24. Be6 Ba6 25. Bf5 Bb7 26. Be4 Ba6 27. Ba8 Bb5+ 28. Kc8 Bf1 29. Kb8 Bh3 30. Bb7 Bf5 31. Bc8 Bd3 32. Bh3 Ba6 33. Bf1 Bxf1 34. c8=Q+ Kd4 … from there, white wins.

[@percyjackson5017]

11:44 why isnt bishop to b7 an option?

[@sidchicken2308]

At 12:20, why not Bb7? Seems like they can’t take it, and can’t go anywhere else to stop the pawn.

[@GroudonsGame]

Why you asking him? Seems like he knows nothing

[@Real-FaZe-Carpet]

2:57 can’t black do Bg2 skewering with an immediate draw?

[@CaitiffFTW]

12:05 Why not Bishop to B7?

[@nemodabuda4817]

Az ugyanúgy nyer.

[@lenonkitchens7727]

I would have played Bb7 instead of Be2.

[@f3m7ar]

The logic is we only want the opposition when our bishop helps us blocking the straight up path for the black king. This way the black king has to either stay put or cede some territory: in the end it got boxed out entirely and black could only move its bishop around, while our old men slowly crawled around.

[@marcinzielenski3202]

At 2:50: After white king to e4 the bishop can deliver a check, and than simply take the pawn.

[@lenonkitchens7727]

Nope, Bg2+ is blocked by Bf3 resulting in a bishop trade, or black's bishop running.

[@shha22]

I think the idea behind the king moves, was that once you play Be2 at ~7:00 min mark, you are preventing black king from moving up the board. Yes he can go to A5, but after Kc5, bishop prevents black king from reaching 6th rank, or going around ( because of opposition you kept).

[@motelghost477]

11:40 White bishop to B7 seems more straightforward to me, you're still forcing either a bishop trade or moving black's bishop of the line.

[@marssang]

I didnt see anyone else explain the logic you missed so I try White has to get the king to b8 since the a6-c8 diagonal is short enough for the king to guard so that the bishop trade can be forced. The whole point of many of the maneuvers is stopping black king from getting there first and blocking white king from entering. You cannot force bishop trade from Kd8, as whenever you go Bc8 black just moves away from either of the 2 diagonals and waits for you to choose where you mive to unblock your pawn, and then guards the promotion square from the other way.

[@srinivasankrishnaiyengar3266]

White Bishop to b7 blocks instinctively and forces bishop trade as Black King is one step away.

[@cerebralcomics]

12:00 why not bishop to b7? Edit: Reading the comments, I see I’m not the only one asking this, hehe.

[@dmaster20ify]

Bishop to e2 stops Nelson from stalemating the King. No. Bishop to e2 is the only move to make the puzzle look like it has a pretty finish. Nobody seems to appreciate a steady winning income.

[@cerebralcomics]

@@dmaster20ifyI’m probably overlooking something, please elaborate. The way I see it, if bishop b7 then black either takes it, moves away with the bishop or moves the king any direction. If black bishop takes white bishop, white king takes black bishop and whatever happens next, pawn still promotes. If black bishop moves away from a6, pawn promotes. If black king moves in any direction, white bishop takes the black one, then black has to move king again and next white still promotes. I don’t see a stalemate, but again, might be overlooking something.

[@dmaster20ify]

@@cerebralcomicsThere is no stalemate. That was supposed to be humour. I scrolled down the KZbin page to write this comment and now Ben finegold is looking at me. MITTENS VS GM BEN FINEGOLD.

[@cerebralcomics]

@@dmaster20ify in that case: r/woosh 😅

[@goodspellr1057]

There seems to be a lot going on. You push the pawn to keep it as far away from the Black King as possible. Then you avoid putting the White King on light squares in order to avoid checks and because you want your own Bishop to move freely so that it can cause a deflection. It's amazing that someone was able to work all of this out before the Tablebase.

[@JohnDoe-ti2np]

The key point is that Black's bishop can control the square in front of the White pawn from two different directions, so for White to win, White has to not only drive the Black bishop away from one diagonal, but also block with his own bishop when Black tries to switch his bishop to the other diagonal. To do this, White needs to position his forces carefully. With the White pawn on c7, he needs his king on d8 and his bishop ready to occupy d7 when Black moves his bishop to the c8-h3 diagonal. But this maneuver works only if Black's king is *not* posted on d6, where it would prevent White's bishop from moving to d7 to intercept the Black bishop. Many of the variations can be understood if you realize that White is trying to prevent Black's king from getting to d6. If White's king is on d8 and Black's king is on d6, then White cannot make progress, because whenever White tries to challenge Black's bishop, Black just switches his bishop to controlling c8 from the other side.

[@WalacaVencano]

12:26 I saw Bb7, giving better result because on the next move, either it will be a queen vs king or queen and bishop vs bishop, while Be2 makes the endgame as queen vs bishop. Or so I think. Can you tell me if it's a bad move and why, please? Thanks by advance.

[@AutPen38]

Bb7 is the most natural move. It's also the best, as it leads to a faster checkmate. Sometimes, one's brain gets broken by looking at all the other variations, while those of us casually watching at home can see the "obvious" solution.

[@kirito3082]

I think in summary the recipe for winning this endgame is: 1. Get the pawn to the 7th, in order to prevent the black bishop from sacrificing we will have to control two diagonals at the same time, this is not possible with a king and bishop if both diagonals are bigger than 3 squares or the edges are far from the pawn. 2. Get the king to B8, at 4:24, the race is not to get to the pawn, the white king can't get boxed out of the B8 square, and it needs to go behind the pawn because the black bishop already controls c8, so gown forward is not productive, and the maneuver with the bishop also gains tempos and box out the black king. 3. Put the bishop on C8 to force the black bishop out of both diagonals 4. Maintain control of the longer diagonal forcing the black bishop to defend from the shorter diagonal 5. Use tempo to put black into zugzwang, it will always be available because black is restricted to a short diagonal I'd imagine this recipe would be applicable to more positions of bishop pawn and same color bishop endgames

[@kentnarron1849]

I see black with a draw 1:43 with Be7. Skewer the king and take the bishop. No?

[@virt1one]

this is a good illustration of why there will never be a mathematical way to calculate chess moves. Future positions are essentially chaotic with all manner of "butterfly effects", that can only be consistently solved by exhaustive search. Only the most basic combinations (like king vs king and rook) can be proven in advance.

[@oleitas_]

This puzzle is divided into three key phases: 1) How fast should white push the pawn? Answer is, as you explained, white has to get the pawn to c7 as fast as possible (immediately) to limit the bishops blocking possibilities. If let's say the bishop can block the pawn at c6 (1. Any other move other than c6) the bishop has tons of possibilities to stay on the key diagonals. By pushing the pawn as fast as possible (1. c6, 2. c7) white also ties the bishop to stop the pawn immediately, leaving white's bishop and king to box out black's king. Also crucial is that if white pushes to c6 but doesn't follow up with 2. c7, black's king has time to move which gives enough time for the king to cooperate with the bishop, which would make it 2 vs 2 for that square and a draw. 2) King moves: As explained perfectly by one of the comments already written, it's basically a zugzwang - the key is that white wants to have their bishop dominating the a6-g1 diagonal to stop black's king from ever reaching a7. that's why opposition is key! White opposes the king from ever stepping in the feasible dark squares (not opposing the king would give black vertical opposition, which black would use to their favor, dictating white king's movement into allowing it into key dark squares as the bishops have a waste off) and then finally, as white pins black's king, once it reaches b4, be2 proves crucial as it blocks both Kb5 and Ka6, which allows the white king to sneak into b8 and control the a7 square, which means that it is white's king that dominates the a6-c8 short diagonal, which white will force the bishop into in the next phase. 3) Forcing black's bishop into the short diagonal - this part is less key, there's loads of ways to do it and the key is again to keep the zugzwang idea in the back of the mind - sometimes moving to a certain square doesn't matter much, it's all about them diagonals :)

[@oleitas_]

oh and white has to play be2 at that specific moment (the first be2 lol) because it is the only moment where the bishop would have the king's support and stop black's king at the same time. this is such a beautiful puzzle due to these little details. endgame art.

[@malkav0488]

White is achieving 2 things: not being boxed out a partial diagonal with king and bishop that black king can't use, delaying it enough to create the opportunity to get to later positions. Pretty fascinating.

[@vtgrphy3907]

When I saw the puzzle, my immediate thought is to use my King to help to trade Bishops.

[@Aragorn.Strider]

I thought I recognised the position and yes, this exact position is on my book "Laeufer und Springer endspiele" by Juri Awerbach (German translation) on page 99 (diagram 180). The book is dedicated only about endgames with bishop and or knight and some pawns. Not 1... Ba6 because of 2.Ke4! Kc3 3.Kd5 Kb4 4. Bg4! Ka5 5. Kc5! Bb5 6.c7 Ba6 7.Kc6 At 2:47 2.Ke4?? is an immediate draw after 2...Bg2+ ... Bxc6

[@warriorofgod2700]

Bishop to b7 works just as well at the end doesn't it?

[@lenonkitchens7727]

No, it works better ;)

[@simens8646]

I think the somewhat odd king and bishop moves at the beginning of the puzzle are all about the fact that the white king needs to be able to infiltrate to b8 rather than d8. In the lines that are a draw (e.g. at 6:04) the black king has prevented the white king from getting to b8. Having the white king on b8 eliminates any waiting moves that the black bishop would otherwise have had on the a6-c8 diagonal.

[@narganoise8211]

3:24 If you move your king to e4 the bishop can go to g2 with check and then get the pawn

[@TheMoldrupable]

Can't you just block the check with Bf3?

[@narganoise8211]

@@TheMoldrupable Yes you are right, my bad

[@Rivertrk]

At 6:32 I think be2 is played to stop the king from moving up as it not only blocks the b5 square but attacks the bishop forcing a reaction out of black and preventing kc5 or ka5

[@patrickbullock1245]

Greetings. You haven't explained why at 11:42 after Black kc5 White bb7 isn't winning given if Black b captures White k recapture followed by pawn promotion to Queen regardless of where Black k moves.

[@danielevans8728]

The key seems to be to not let black king gets to b6

[@jamesgowing3856]

Why didn't the black bishop go to e2 next to the black king on d2. That way the white bishop on h5 could be taken as the white king would need to be moved. The game then ends in a draw.

[@jespernorgaard3795]

1.c6 Be2+ 2.Kg3! Bxh5 3.c7 and the c-pawn can't be stopped, for instance 3...Bg4 4.Kxg4. Black must return 2...Ba6 3.Kf2 Kc3 4.Be2! Bc8 5.Ke3 Kb4 6.Kd4 Ka5 7.Kc5 Bf5 8.c7 Bd7 9.Bc4 Bf5 10.Kc6 Be4+ 11.Bd5 Bf5 12.Kb7 Bg4 13.Kb8 Kb6 14.Bb7 Bf5 15.Bc8 Be4 16.Bh3 Bb7 17.Bf1 and Black is in zugzwang 17...Kc6 18.Bg2+ and White wins.

[@小聖-q2o]

Exactly the same thought. However taking white bishop would be blunder. The pawn just go straight to the end

[@cristoferwolz-romberger3835]

At 2:55; 2:Ke4 is followed by ... BG2+ followed by Bxc6 Edit: never mind: BG2+ goes 3. Bf3 Bxf3 3. Kxf3 with a win.

[@skylardeslypere9909]

11:43 can we also go Bb2? It also cuts off the bishop from that diagonal (which was not possible before since the king would defend black's bishop if they took on b2). If black moves away, queen. If they don't, trade the bishops and get a queen later.

[@sidchicken2308]

I think you mean Bb7, but yes.

[@skylardeslypere9909]

@@sidchicken2308 Oops, you're right. I meant Bb7

[@chess_player007]

10:55 Be2 - Bb7 Bb5 - Kb5 Kb7 and win for white.(similar idea like in 14:00)

[@danmor5451]

4:31, 5:32 the reason these exact moves are winning ones is cause e3 field is the only one where king guards e2 and f3 for bishop to keep both of diagonals 'safely attacked'. The idea is not the opposition of kings, i guess. Moreover, this is the reason why we didnt move king far from e3 earlier, we pushed the pawn instead to force black bishop into top left corner with just 3 reasonable options left. Great puzzle!

[@jaseyn]

Just amazing. Please, do this type of video more often. This hard position puzzles brings a lot to a table. Especially end-games. Very educational. Amd you are great in explanations. Wish you all the best!

[@keymasta3260]

I mostly like puzzles Mate in 2 or Mate in 3 but this puzzle Mate in 33 is also nice

[@terminator_x.24]

6:50 in my theory the bishop was necessaey to avoid king from getting it to b5 square and the king opposition forces the black king to ogher way , affer few moves black was able to use the same bishop to block and reach it pawn with black king at a distance

[@jonathanwork7070]

at 3:15 Black could play Bh3 and white does not have a good way to stop the bishop from controlling c8. The puzzle involves finding a way to get the king to b8. The king on d8 will not be able to stop the bishop from controlling c8. I can explain about bishop endgames with one side having a pawn on the 7th rank. With a bishop pawn, the king has to be in a certain position to win. A knight pawn is winning if the king is defending the pawn. If it helps, I can make a video explaining this.

[@Evens4102]

4:19 The whole beginning of the puzzle is to prevent black king from getting C4 because if you do that, then you can box out the king that is the whole point behind the 2 pawn moves and ke3

[@matthewbrown7166]

All I can see/say is that you need to keep "forcing the issue" as white. The idea seems to be reducing (if that's the right word) black's options. White eventually gets the Queen. Far easier said than done. Marvellous puzzle. Keep em coming!!!

[@meister-t]

Why sacrifice your bishop if you can trade it? 11:50 in this position, B-b7 would work better

[@drincmusic2769]

7:54 bishop f1 stops king to b5 which if black had their king on b5, it would allow the black king to gain a drawn opposition.

[@chriswatson7965]

At 3:23 moving the white Ke4 allows the black bishop to cover the c8 square via h3. Moving the pawn first forces black to cover the c8 by moving the black bishop to a6. I will also add that white's aim is not to get the king to the pawn but to get to black's bishop. So the king and the bishop need to manoeuvred around to push the black king to the left and stop it from protecting the bishop.

[@Karadjanov]

There is also a much more immediate explanation why e4 does not work: If Ke4 then Bg2+ and Black simply sacrifices the Bishop for the pawn.

[@alex_zetsu]

This and a few other of the other presented puzzles show how being ahead 2 pawns by doubled pawns is not "basically 1 pawn ahead." The addition of a white pawn on c3 would make the endgame trivial.

[@Sunnernite]

3:30 if you move Ke4, black can also go Bg2, skewering the king, take the pawn and it's a draw

[@fizzythrows]

Ke4 is also winning according to stockfish

[@Idiot_Indians]

No, it's not skewer because u can block it with Bf3

[@gordonherring2055]

11:05 Really? Your mind had to be tired by then. If Black keeps the Bishop on the diagonal, it is taken by the King on c8 or the Bishop on b7. If the Bishop moves off the diagonal, Pc8 = N! (okay, just joking, Q!). If the King moves then Bb7! kicks the Black Bishop off the diagonal or White gets his trade. Now I'm wondering what Mr. Crum was thinking at 11:58.

[@AutPen38]

This appears to be one of those fascinating puzzles where experts and even the person that set it can't see the obvious solution but lower-rated players can. Studying all the variations must have broken Nelson's brain. I'm sure a well-rested version would look at this video from 11 minutes and see that Bb7 obviously wins more quickly.

[@LPChip]

At the very end, I finally understand all the manouvering. It is indeed a stalemate because black will just keep moving the bishop away, and it is that why you have to attack it in a very specific way. At many times I was like, just put the king on D8 first, then our bishop on C8, and the next move we can move it out of the way to promote to a queen and if they take our bishop, then we just take back. But black is not going to do that. They'll keep moving the bishop in and out and using tempo to ensure that its not being captured to force a stalemate.

[@benl9694]

I'm sorry, I'm not great at chess, but I don't get it. If white first move pawn to c6, why doesn't black respond bishop to e2 check. Then black picks up white's bishop and should be able to play out a draw. What am I missing?

[@SparkSovereign]

Black doesn't have enough time to get the bishop back to a safe place from which to control the queening square. After the capture, you've only got one move to get into position and the king is probably waiting for you on F4, controlling G4.

[@benl9694]

@SparkSovereign so bishop to e2 check, king has to move bishop takes white bishop even if you push pawn bishop can move to g4 and prevent pawn from getting the promotion

[@benl9694]

Sorry never mind. If the king moves to f4 after check then the bishop can't move to g4 after taking white bishop

[@DonaldRoy-nr9xe]

4:35 prevents the "option" to put white king in check, maybe?😮 3-4 steps ahead which changes momentum/tempo of White's pieces and ultimately draws/prevents the window to win?

[@ronbelanger8812]

Well done, Nelson. Aspirin in the medicine cabinet.

[@arpuslaet29]

Great video!! We need more of these end game concepts to take advantage of these common positions. Please do more of these videos.

[@triplayzatd1347]

1:49 don't bissop to e2 work because it skewer the king and the bishop

[@RoderickEtheria]

4:35, the reason the king moves left orthogonally there is for the bishop to move to attack black's bishop.

[@peterbauer7271]

What an instructive puzzle. Fine end game study it’s pretty deep.

[@jackwells8107]

I would have thought white bishop to b7, so they either take and lose their bishop, or the white space is free. With the bishop to e2, I think you have to do it to keep the black king from moving to b5 and having to go to the a row.

[@AutPen38]

In this case, I believe the "obvious" and most human move (Bb7) is actually the best, as chosen by tablebase engines. I think Nelson's brain got scrambled by looking at all the other variations, so he didn't see it.

[@matthughes1341]

2:54 the reason it doesn't work to do any other move is that it will allow for black Bxh3 without king cover for block

[@zombiedino184]

I’m no master but it seems like Be2 at 6:18 serves the purpose of cutting off the king from a6 in later parts of the puzzle like at 7:55

[@hajanejdjsms]

At 11:30 it also works if you move bishop to B2

[@ErJitano]

You mean b7?

[@hajanejdjsms]

​ Yes

[@TheEthikos]

Why at 11:40 could you not just block the black bishop by moving your bishop to B7?

[@AutPen38]

You can and you should, because it's obviously the best move. I think Nelson's brain got broken by trying to understand the earlier variations, so he overlooked the simplest and best solution.

[@DJF1947]

It would be interesting to know whether Crum had any kind of life.

[@No_Name78328]

4:17 push the pawn to promote and check the king

[@olivercoates7076]

1st move: c6, because you have to clear that square before the bishop can cover it. ...Kc3 2nd move: c7. Ke4 lets the black king stay on the same file and approach. ...Bh3 will cover the capture square and you can no longer block with Bg4 because the white is out of reach to defend the it. Therefore, playing c7 demands the black bishop decide h3 or a6 NOW, preventing Bh3 in the future. ... Ba6 3rd move: Ke3. Now and ONLY now that the black bishop is on the left side of the black king, does he has to worry about the skewer on ...Kc4 4. Be2!, which would leave him without a way to stop the promotion. ...Kd4 needs to be stopped or the black king will interpose between your king and the pawn and force the draw. So to stop that we need opposition. We don't, however, really need to 'race' to the pawn, we just need to block Kd4 with opposition. Ke4 would open up Kc4 (letting the black king stay on your pawn's file), after 3. Ke4 Bb7+! 4. Ke5 (the king notably can't take the opposition from the pawn's file because its being attacked from that diagonal), ...Kc4. Kc4 becomes an option again and black again can stay on the file with your pawn because Be2 is no longer a skewer once the black bishop is on b7. Letting him move there with tempo is bad. Ke3 is the only way to oppose ...Kd4 without inviting Bb7+ ... Kb4 4th move: Be2. Now, with the black king only 3 moves away from taking your pawn, he no longer cares about the skewer. He doesn't care about losing his bishop via 4. Kd4 Kb5 5.Be2+ Kb6 6. Bxb6 Kxc7. As shown 5. Kd5 or others are no better because the black king will successfully control his bishop's corner. Instead, the white king and bishop need to work together again to timely cover the squares the black king wants. 4. Be2 prevents ...Kb5 entirely. If ...Kc5 5. Bxa6 and the king is too slow to stop promotion. If ... Bxe2 5. Kxe2 and the king is too slow to stop the promotion. So the black bishop has to move again. This was a repeat of the last theme and principle of the puzzle: For black, keeping the opposition/staying on the file with your pawn is only valuable if he is not at risk of losing his bishop with no way of catching your pawn. Previously that mean leaving the file to avoid stepping into the Kc4 skewer. Now it means not returning to the file with Kc5 because of the attack on the bishop. ...Bb7 or Bc8 5th move: In either scenario, the key thing is the same as it always was: keeping the black king cut out of the action. Now, and only now, that both the b5 square is no longer passable for the black king, we need to cover c5 by taking opposition. We were only able to ignore this last move because the initiative brought by attacking his bishop. Black's king can't go forward because your bishop controls the white diagonal. You hold opposition so he can't 'cut across' the bishop's attack pattern. He can only climb towards the edge of the board. His bishop is tied to the defense of the promotion square on one diagonal, but can be attack along the other. After some shuffling, black must move his king to the edge of the board or otherwise invite white's king into controlling the b7 square, after which white can bring the bishop in there in such a way that black can't circle around to cover promotion fast enough.

[@MaskOfCinder]

You should try to collab with some GMs and have them explain positions like this.

[@dmaster20ify]

The puzzle that hurt your brain. Looks like a simple endgame. 1. Kf4 ( to get the king to escort the pawn) 1... Ke4 ( 2. Bf3 ) 2. Ke5 and from here I think its just technique. Get the King to d8; play ring around the rosie with the bishops until black can no longer control the c8 squre then promote.

[@dmaster20ify]

Alright so my analysis was wrong. But why does the solution make your brain hurt? All of the moves are logical. I just forgot that I needed the King on b8 to win.

[@jsterdawg72]

Towards 3:11 when you need to push the pawn up instead of moving king it's because bishop G2 pins the king to the pawn, have to move king and it's a draw that way - edit oops didn't see the bishop preventing that, interesting but maybe it plays off that?

[@robertthebard]

3:04 after the King push to e4, Bishop G2 check gets the pawn.

[@Ewheii]

Couldn’t you also go Bb7 at 3:21? Blocking the bishop out, they can’t take or you take with king. If they move their bishop you promote. I believe that also works, correct me if I’m wrong.

[@driveral1305]

2:56 you have to push the pawn. Ke4 doesn't work with the pawn on c6 due to the check skewer. Any other king move is a drawn endgame because the black king and bishop can block out the white king.

[@shha22]

there is no skewer really, since you can block the check with your own bishop

[@LuizFelipe-fk6it]

The whole purpose of moves like Ke3(Protecting e2) and Be2 was to get control of the diagonal, so when the King gets boxed in he cant go up

[@DrLawIrk]

This study is a masterpiece. So deep.

[@gerrittoet5318]

Nelson, this is a variation on an old Centorini puzzle ( 1856 ) with the white king on c8, the bishop on d8 and a pawn on b7 , the black king on c6 nd the black bishop on h2

[@masonplayzz93]

12:11 doesn't Bb7 work too? It does the same thing as Be2 if I saw everything right

[@BrawlStarsPearl-Stats]

11:44 Bb7???

[@jimhardy8686]

@4:15 Ke3 because it protects your Bishop when you go Be2. If Ke4 then you can't get your Bishop to e2, so it doesn't get to that diagonal in time. @1:07 If Ke4 then I *think* black goes Bh3 and gets your Bishop out of the game. Not sure about that though.

[@ZyreBlox]

12:13 hey nelson why dosent Bb7 work here? it still blocks the other bishop and he has no way to defend the c8 square

[@ritgoswa]

3:09 there's Ba6 And the original idea to stop that is Bg4 and run the king to b7 but the king is blocking you from going to b7!

[@drincmusic2769]

I think that the main thing for why you have to do the move order in the beginning is because you need to be on the left side of the pawn in order to play against the bishop when it's on the left side of the pawn.

[@Phantom-mg5cg]

12:00 What about Bb7?

[@Chaturanger]

At 11:25 why not Bb7? Instead of Be2

[@christianfrost8660]

So White's plan was to sacrifice the White Bishop in such a way that it causes the Black Bishop to lose control of the C8 square?

[@trottedazur5183]

11:41 but you can also play Bishop to B7 and win the game

[@sandermeesters192]

at 2:55 black can just skewer and get the pawn that way

[@jakubvranacz]

11:35 Another winning move should be Bb7.

[@thegamer4]

2:25 i wonder what happends after Be2 check from black

[@Together4.4M]

11:46 What about Bb7?

[@nevenkapoledica9382]

that is best move, win instant

[@Markaras]

11:44 why not bishop b7?

[@gabegreener5038]

The 7:15 threat on the bishop makes black have to move it then after grabbing opposition the bishop is blocking out the king along with your king

[@christopherheckman7957]

14:05 In this line (Bb7), a true Zugzwang shows up (after Bb5): White cannot win if Black can pass instead of moving. In the previous line (Bc8), a pseudo-Zugzwang shows up (after Be2); White can win if Black passes (Bxa6, etc). Nelson, you really need to make another video once the principles become clear. This isn't a flashy puzzle, but it still is deep, especially considering those "only move" maneuvers. P.S. The new channel isn't working; the error message is: "This account has been terminated for a violation of KZbin's Terms of Service."

[@jasonc0065]

Once white plays Kb8, there is nothing to it. Drive the bishop to the short diagonal. Threaten Bb7. If ...Kb6 and ...Ba6, play a waiting move.

[@sobservando]

11:52 Why not Bb7?