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Counting knight moves

Counting knight moves

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s

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Quick! What's the minimum number of moves a knight on g6 needs to get to e4 ?

To answer this question, most chess players will simply start to mentally move their knight around, counting the moves, until it lands on the desired square. Let's say you counted 4 moves: e5-g4-f6-e4 That's one way to get there, and so is: f8-e6-g5-e4. But is there a shorter route?

To answer that question with some measure of certainty (as opposed to just guessing), most chess players would need to try a number of alternate paths to e4. This might take an inordinate amount of time in a game, and when the player has the answer, they might even need to go through the moves again to double-check their answer, taking even more time.

And what if the player was interested in more than one destination square for the knight, or in the minimum number of moves it would take for knights starting from two different squares to reach the same square? Depending on where that square was, coming up with an answer you felt confident in could really take a long time and be very error-prone using the ordinary method of counting knight moves.

Fortunately, there's a better way. I'm a fan of obscure chess books, so when I was at a local chess store the other day, the book "Knight Moves" by Charles Alexander caught my eye. In it he describes a relatively simple method, which he calls "Alexander's Technique", to count the minimum number of knight moves it would take a knight to move from any given square to any other square.

Alexander's Technique consists of a number of rules-of-thumb which the player would need to memorize and apply. The rules range from the incredibly simple -- such as learning that the only times it would take a minimum of 6 moves to get a knight from one square to another is if the knight starts on one of the corner squares (a1, a8, h1, h8) and wishes to go to the diagonally-opposite square (ie. from a1 to h8, h1 to a8, etc...) -- to a number of more complex (but quite easily learnable) rules.

It only took me a few minutes to start applying the rules after I'd read the book, and maybe another ten minutes to half an hour to completely internalize them... and after an hour or so of practice, I feel completely confident I'd be able to quickly (certainly under about 15 seconds, and often as little as a second or two) to figure out what the minimum number of moves it would take for a knight to get from any one given square to any other.

The method can also be used to determine the minimum number of moves it would take a knight to get to groups of squares. For example, if the knight is not on one of the corner squares, you immediately know that the minumum number of moves it would take to get to any other square can not be greater than 5. The minimum number of moves it would take a knight to move to other groupings of squares, such as any black or any white square, could also be easily counted.

Alexander's Technique does have its limitations, the most obvious one being that the presence of other pieces on the board might delay or completely stop the knight from reaching a given square in the minimum number of moves. For example, some moves might be illegal given the situation on the board at a given time (such as having a piece of the same color as the knight block one of the squares the knight needs to move to), or if the knight gets captured on its way, etc... In this case, the player is pretty much on his own in taking account of these possibilities. Still, he can be certain that the knight will not reach the destination square in less than the number of moves Alexander's Technique tells him it will.

Another limitation is that the player could still make a mistake in applying Alexander's Technique, perhaps requiring a double check of some sort (by either re-applying Alexander's Technique, or manually counting out the moves).

Still, given what Mr. Alexander set out to achieve with his method, I'd say he admirably reached his goal.

One other thing that I should mention is that this is a really thin book. All together it's only 82 pages, about 20 of which are exercises, answers, and the index. Also, if you're just interested in learning the technique itself, without knowing why it works, you could probably skip the first 40 pages. And, if we also omit the 7 pages of examples of the technique in action, that only leaves about 8 pages that you'd have to read to learn the technique.

Of course, mastering the technique will require practice, so I advise going through the examples, and doing at least 6 to 12 of the exercises (which shouldn't take you more than an hour or so). After that, you'll be counting knight moves like a pro! 🙂

r

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Originally posted by synesis
Quick! What's the minimum number of moves a knight on g6 needs to get to e4 ?

To answer this question, most chess players will simply start to mentally move their knight around, counting the moves, until it lands on the desired square. Let's say you counted 4 moves: e5-g4-f6-e4 That's one way to get there, and so is: f8-e6-g5-e4. But is there a shor ...[text shortened]... hour or so). After that, you'll be counting knight moves like a pro! 🙂
obviously, you stated your source, but couldn't the author still sue for giving away his information freely, meaning that you're damaging his profits?

MR

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Originally posted by rubberjaw30
obviously, you stated your source, but couldn't the author still sue for giving away his information freely, meaning that you're damaging his profits?
Unless I missed something, synesis didn't give the detailed methods, only a general summary. So as far as I can tell, he did nothing wrong. Gee, if everyone used your standards, there would never be any book reviews!

J

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Even if the method was thoroughly explained in the previous post, I doubt that the poster would have infringed on the book copyright. I'm not an expert, but if that was the case almost every chessbook (or cookbook, or the various "for dummies" books) would be an infringement on previous work.
My understanding is that the copyright protects the author from extensive citation or plagiarism of his work, not from talking about his ideas and repackaging them. That would be more a patent than a copyright, and I woud be very surpised if the dude filed one on methods to count knight's moves - and even more suprised if it was accepted!
Anyway, I'll see if I can get ahold of a copy of this book, I'm intrigued by the method.

J
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Originally posted by rubberjaw30
obviously, you stated your source, but couldn't the author still sue for giving away his information freely, meaning that you're damaging his profits?
Interesting book... probably will check it out now..

(The author would be pleased!)

MR

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It does seem to be an interesting (but thin) book. But I'm wondering how often someone needs to count these knight moves from one square to another square. Any opinions about whether the method is used enough in games to warrant learning the method?

STS

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The horsie moves like an "L" and can jump over pieces. It also changes the color of the square it lands on with each move and attacks the opposite color square of the color it is on.

Or so I'm told.

MR

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Originally posted by Sam The Sham
The horsie moves like an "L" and can jump over pieces. It also changes the color of the square it lands on with each move and attacks the opposite color square of the color it is on.

Or so I'm told.
Amazing! The stuff I learn here...

S

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Originally posted by Mad Rook
Amazing! The stuff I learn here...
The further up the board they go, the stronger their kick.

s

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Originally posted by Mad Rook
It does seem to be an interesting (but thin) book. But I'm wondering how often someone needs to count these knight moves from one square to another square. Any opinions about whether the method is used enough in games to warrant learning the method?
Well, counting knight moves can become quite useful in endgames involving knights... and also sometimes in the middlegame. Though I couldn't give you any stats, I know it's happened in my own games from time to time, and up till now I've had to rely on the "ordinary", error-prone method of counting moves.

As to whether that happens often enough to take it worth your while to spend all of maybe one whole hour learning something new... well, all I can say is that we've all probably wasted far more than that reading chess books that didn't teach us anything new at all. 😉

MR

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Originally posted by synesis
Well, counting knight moves can become quite useful in endgames involving knights... and also sometimes in the middlegame. Though I couldn't give you any stats, I know it's happened in my own games from time to time, and up till now I've had to rely on the "ordinary", error-prone method of counting moves.

As to whether that happens often enough to take i ...[text shortened]... sted far more than that reading chess books that didn't teach us anything new at all. 😉
Thanks for the input! I think I'll add this one to my "get list". Too bad it's out of print. I'll actually have to scrounge around for it and fight the other guys here who have also expressed an interest in it. 😀

s

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Originally posted by rubberjaw30
obviously, you stated your source, but couldn't the author still sue for giving away his information freely, meaning that you're damaging his profits?
First of all, this is a very obscure, niche chess book... so I doubt the author has had any profits to speak of.

Second, in writing the review I made sure not to reveal so much that buying the book would be worthless. I know that writing little chess books like this is often a thankless task, and could tell (by reading the first 40 pages, which described why the method worked, and realizing how many hours it must have taken Mr. Alexander to figure out his method) that what the author did was a true labor of love.

Furthermore, the method works as advertised (which is far more than you can say for many other chess books) and is relatively easy to learn. So I feel nothing but gratitude towards Mr. Alexander for his efforts, and wouldn't want to cut in to his profits (assuming he had any). Quite the opposite. I think he deserves to be more widely read, and hope he gets rewarded for his hard work.

Third, I just wrote and posted a glowing review of his obscure little book, which no one here would have probably heard of for the rest of their lives had I not mentioned it. And my review has already gotten a number of people interested in reading the book. I've heard of people getting sued over negative reviews, but this could be a first if he sues me over a positive one. If anything, he should be paying me. 😉

Finally, as other people have mentioned, there is no legal basis for suing me, as I didn't violate his copyright. Even if I'd quoted verbatim from his book (which I didn't), a reasonable amount of quoting out of a book is allowed for a review, per the Fair Use doctrine. See http://en.wikipedia.org/wiki/Fair_use

Mahout

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The same book gets a good review on the chessbase website

s

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Originally posted by Mahout
The same book gets a good review on the chessbase website
Yep. I read that review just before writing mine. Unfortunately, that reviewer hadn't read the full book before writing his review, so he couldn't comment on whether the method worked or not.

Also, the chessbase reviewer thinks that to quickly learn the method, you'd have to be a "disgustingly Einsteinian type who can think in four dimensions". I don't think that's true at all. The chessbase reviewer probably got that impression from only reading the first half of the book, which describes why the method works (which I admit, can be pretty intimidating). But towards the end of the book the author simplifies the method down to a handful of rules-of-thumb, which I think anyone of average intelligence will have no problem learning and applying with a bit of practice.

I'm actually quite impressed with just how clear and simple the explanation and method are, considering the complexity of all the possible knight moves on a chess board.

DD
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Originally posted by synesis
Quick! What's the minimum number of moves a knight on g6 needs to get to e4 ?
4

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