"Space" is quite loosely defined in chess. Any or all of the definitions you offered would be valid.
The basic idea is well established: the side with more space has more freedom of movement, while the opponent is cramped. But the actual mechanics of counting it will vary from one chess teacher to another.
GM Larry Evans wrote a book back in the 1950s called New Ideas in Chess, in which he introduced his own methodology for assessing Chess positions on the basis of a breakdown into strategic elements including Space, Time, Force and Pawn Structure. This "static analysis" was supposed to compliment the better-known "dynamic analysis" of I-go-here, he-goes-there.
I can comment more fully on this if you are interested in the topic.
Thank you. This is a really good I example; it helped me think more carefully about the concepts and I think I understand them better.
blueemu, thank you as well. Yeah, if you have time to comment more, that would be great.
GM Larry Evans' method went like this:
Space:
Ignore your first three ranks, because they are fully guarded in the initial chess position. Starting at your fourth rank, count all the squares that your Pawns and pieces guard. Guarded squares are counted if they are empty, or occupied by an enemy Pawn or piece, or by one of your own pieces... but NOT if they are occupied by one of your own Pawns. This is your Space count.
*** NOTE *** It is VERY useful to count Space by TWO different methods and then subtract the totals. This procedure will give you a number representing the discrepancy between the two methods of counting Space, and if you have chosen a meaningful "second count" methodology, this discrepancy will actually represent something important.
The method I use for a "second count"... not found in GM Evans original book... is to make a second count using identical criteria to the first count; but instead of counting each guarded square once, I count it as many times as I have pieces and Pawns covering it. So if I had a Pawn, both Knights and a Rook guarding the e5 square, I would count it as four points instead of one (unless the e5 square was occupied by one of my OWN Pawns, in which case it counts as zero by the above criteria).
When you subtract these two counts, the discrepancy represents the degree of coordination of your pieces. That should be clear by examining a couple of edge-cases:
a) If my power is spread evenly across the front, so that many squares are covered but each one is only covered once, then my first and second counts will be identical and the difference between the two counts will be zero. My coordination will also be low, because my Pawns and pieces are spreading their pressure out instead of trying to focus it.
b) If my power is concentrated towards only a few squares, there will be a large difference between the two counts... and on the board, my coordination will be high because my pieces and Pawns are focusing their pressure instead of spreading it out.
GM Evans goes on to describe his method of counting Time and Force, and then he offers a "Results Matrix" advising the player how to handle the position if he is ahead in Space, or behind in Space (and the same for ahead-in-Time, behind-in-Time, ahead-in-Force, etc.
This is great; I like being able to have a formula, if you will, to calculate a specific value - it's more tangible - can be compared and thought about. I think the "Results Matrix" would be really valuable to understand all the implications of a position. Thanks again for your help.
It's useful, yes... but you need to remember that chess to too vast a topic to really be squeezed into a narrow methodology. So there will always be cases where the "static analysis" gives you good generic advice that has NOTHING to do with the specific situation in front of you. The dynamic analysis... the "I-go-here, he-goes-there" analysis... must always take precedence over any simple counting method like this one. But the static analysis can often be used to guide your thoughts as you calculate variations.
I can post a few sample position (or follow a sample game) later, to illustrate both the counting methodology and also its application in a real game.
The following is a good illustration of space:
Hello
This is my first post so please forgive me if the topic is not appropriate or for any other silly thing....
There are two topic that I have been confused about for some time. First, why and when should the a2 and b2 pawns (for white) be moved; for example, I see moves a4 or a3, b4 played. But even in the annotated games I have reviewed, there is no good explanation as to why the moves were made. The second is about "space", or "gaining space", what exactly does that mean? For example, I have read comments that indicate pushing a pawn, at least in certain positions, provides more space.
Regarding the second topic, I used to think space meant space for my own pieces to move around, like behind a pawn chain. But I think I have read that space means the number of unprotected squares that my pieces have the ability move to for any given position. Finally, I have read things that lead me to believe space is the number of squares protected by my pawns that are not in turn protected by my opponents pawns - sort of a subset of the second idea I mention. For all I know, space means all the above.
If somebody could help me answer these questions, I would be a much happier person!
Thank you