K & 2 B vs. K

This one is causing me some troubles.  The example in the book is easy because the king is pretty much cornered.  Cornering the king is what I'm having troubles with.  Any help would be greatly appreciated.

This is from the book.

Here is an example where the king isn't already beaten (mine).

22 moves seems like too many.

Do you have any advice on how to do that?

This is what Fritz says:

I should see what it says when the king is in the middle because I see now that the king is actually cornered..

It makes me feel like a sheep dog.

Glad I found this thread ClavierCavalier, because it's a problem I've been wrestling with  for a while now. Not a headache mating from any starting position in say, 25 moves but how to cut it right down ?

 The position you show is probably one of the easiest because you've placed the black king in the corner & that's the mating square. Harder when you start with him in the middle !

 I've been refining my technique for a few weeks & I think I must be close because I come to the same number of moves as Fritz - 15, although I don't use the same method.

 It's worth pointing out that mate can be achieved with the black king on a corner square or one adjacent to it but on no others as far as I can see.

There are a few moves in your diagram that might be improved and I've included annotation in my diagrams to explain this. For instance, there's a shortcut available in some positions which I've only recently noticed & shows the power of two bishops working together.

 These next two diagrams have the same starting position that you used but show whichever way the king tries to escape, he still becomes trapped:-

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This diagram has black's king starting from the middle of the board & involves more work to drive him towards the edge.  It also shows the variation in which mate is carried out on an adjacent square:-

Hope this is of some use to you & if you can see any mistakes or problems in them please message me - for example have I used the most obstructive moves for black ?

I havn't sorted this out fully for myself yet !

So you're trapping the king first, then you bring your king up and pivot your bishops around it.

Here is one I tried.  It's 19 moves, so check to see if there are any errors. Instead of keeping the king as close to the bishops as you did, I used it to cut off 1 file when I could.

Looking at it just now, I see some errors.

18? 

I like your latest thoughts on this Clavier, it's all sending me in a different direction (again). I was looking for a reliable, foolproof method - you know when you're tired at the end of a long game & don't want to do too much deep thinking ? But I really like your use of the king there to drive the enemy towards the corner.

I think there may be some faults in your diag's, as you suggest. For instance in the first one, 8...Kf6 instead of g6; wouldn't that be worse for white ? I played that on & it comes in at 20 moves instead of 19.

I'm also not sure about your 16...Kh8 - isn't Kg8 better for black ? It may offer the chance of escape..  The only way of avoiding this that I can find is 16.Kf7 - nothing else seems to work. After all, the two kings have to be in opposition before you can execute mate.
I've just realized 10...Kg6 may be wrong - should be f8 ? The king can jump-over the diagonal but it can still be finished in 19 moves so not that bad after all. 

Edit: Move 14 should be ...Kh4 not as shown. To avoid this play 14.Bg3 instead of h3 (too late to include in my diagram)

I've included my alternative moves in this diag.

My final one was around 4.  I got to the point that I was losing bishops, so I called it quits.  Pointing out these errors is fantastic.  I'm glad you agree that one can cut down the turns with my method.  I took some of the principles you showed me in your diagram and thought about how the king helps push the opponent back to queen a pawn or to mate with a rook.  A master level player could probably cut it down more.

I think the next one we should tackle is this one.  I have a feeling the bishops might be able to swing around the king and cut down some time.  I'll come back later tonight and post my answer, and hopefully you'll have one.

This is my second attempt at this one - the first vanished from the Game Editor, I think when the site went down earlier. I suddenly got the 'Play Vs The Computer' screen & I lost a carefully prepared diagram. What a great site this is !

I think I've reached the limit of what I can do with this one - between about 19 & 22 moves is the least I can get it down to. See how you get on, you may find something better & shorter (I'm still feeling a little jet-lagged after last night).

The problem I have with the bishops is that there don't seem to be any easy rules of thumb as there are with K+2xRooks - you have to keep thinking hard all the time.

Anyway, see what you make of this:-

I quite like the video above - covers many of the points we've discussed on this thread.

Great, my post completely disappeared.  I hope it doesn't reappear after posting this one.

I started right away with using Fritz so it'll record my moves and make the best king moves.  It wouldn't let me use your method.  Here is what it did that changed it.

Mine was 21 moves.

I think we're both getting it well, though.  It seems like 19 moves might be the best, unless the king is already cornered.

Ah - yes, the vanishing post. I get a lot of those on this site - messages too. I think the 'Submit' button should be re-labelled 'Annihilate' - haha. It's become so bad for me, I don't even try posting complex comments (with diagrams) all at once anymore: I submit the text first (which I also save in Notepad), then add any diagrams as an edit - works much better!

 I've reported this but I don't think the tech staff know what to do about it.

 Back to the chess: Not familiar with Fritz or any engines frankly but a little surprised at the results you got. Hmm..wouldn't let you play my moves ? They seemed pretty good at the time but I can't compete with a machine.

 Something strange here though because I thought I saw a better line at move 6 & played it through & had mate in 15 moves !  Think I must have made an error but can't see it - could you check it through for me ? 

{and would you believe - I just lost all of this. Good thing I'd saved it}

.

From your start position, my chess engine, playing both sides, mated in 10moves as follows:

1. Kd6 Kf8 2. Bg6 Kg8 3. Ke6 Kf8 4. Kf6 Kg8 5. Bc5 Kh8 6. Be4 Kg8 7. Bb4 Kh8 8. Kg6 Kg8 9. Bd5+ Kh8 10. Bc3# 1-0

Just out of curiosity, whose starting position did you use?

Alright, Stephen_33, this is what the computer says:

I'd also like to know whose starting position & what engine you used oliverwood199. I don't remember seeing that one anywhere on this thread !

Undaunted, I thought I'd give it a go & once I'd put a PGN together which took a little time, I got this (unexpected) result on a first attempt:-

I just idly entered what seemed like good moves for both colours & got the same result. If black plays 1...e8 it's less easy - I'd like to know what you come up with then.

(Would people please post sequence-type diagrams instead of just positions: That way we can all extract the PGN from your diagram & paste it into the game editor/analysis board & play around with it)

Clavier, it may be time to invest in a new engine ! If I can do better than one, there's something wrong.
I looked at the sequence you posted & think move 12.Bg3 is just bad.

Here's my version:-

I'm getting to the point where I can't wait to be in this position in a game but I don't suppose that will happen any time soon & if it does, I'll have forgotten most of this. I just hope some of it sticks.

Can you think of any other starting positions that might be interesting to try ?

You know, I honestly thought that Fritz's moves didn't seem to make sense.  I'm going to play around with it and see if it's set to be dumb.  Maybe it's just set on too low of a setting, and it keeps that difficulty for analysis?

I think one with a pawn and a king might be interesting since it'll require isolating the king from the pawn before doing the mate.  Unfortunately, right now, all of the ones I think of are going to be too easy or result in a draw.

So satisfying to know these engines aren't perfect - there's still plenty of room for 'organics' like us in the game !      

King & two bishops vs king & pawn ? - sounds fun. If you post a diagram,
then I'll give you my thoughts.