Yeah, Kaufman made me look at rook pawns differently, I count it as a very small plus to capture a rook pawn toward the center in the opening or middlegame (everything else being equal).
It doesn't seem you appreciate though how dangerous an "outside passed pawn" is though. A passed d pawn blockaded by a knight doesn't hurt he knight nearly as much as a rook or knight pawn pawn. A passed rook pawn, whether it can queen or not, will decoy enemy forces out of position.
how does a rook and 2 pawns compare to 2 unoposed bishops?
how does a rook and 2 pawns compare to 2 unoposed bishops?
That depends on the specific position quite a lot.
Well, I'll give it a go.
. . .
Queen: 13
Rook: 8
Bishop: 5
Knight: 3
Pawn: 1
. . .
Can anyone check my calculations for any errors? Thanks!
Neat, thanks. I don't want to check the calculations though :)
ok :)
yes roi, i think even though it seems not so important i think giving the concept a name makes it easier to remember and apply it. I knew it already when i read but it seems to come up faster when i have a name to it.
I am sorry if my question sounds stupid but I must ask: why is a rook (5) worthier than a bishop or a knight (3) in terms of exchange ? I mean all of these pieces seem to be on the same level to me, they just have different movement possibilities and utility.
If one had to be worthier I think it would be the knight because of its ability to jump over any other piece on its way and its particular "L" movement which can set up terrible forks as well as making it the only piece able to threaten the queen without putting itself in danger.
So why is a rook worthier according to this points system ?
Thank you.
PS: I am sorry for any mistake, english is not my native language.
statistics and common sense.
As people mentioned before, a rook is more valuable as it can attack more squares, mate a king (a bishop/knight cannot do this).
Also, they see all the games with a bishop vs. knight, lets say, and i think in a bit more than half (55% or so), the bishop wins, so they say it is more valuable.
And if I went further by placing more obstacles on the board, the value of the bishop would go down considerably, while the knights' value would not change as much, for example.
Those calculations look right to me.
Piece mobility as it relates to piece value is discussed extensively in Dan Heisman's book 'Elements of Positional Evaluation' (see http://www.chesscafe.com/text/review742.pdf). He used a slighty different approach than you did, and he refers to this as a piece's "potential mobility" -- simply a sum of all moves (or captures for the pawn) with no obstacles on the board. Then he added two other 'mobility' elements -- "actual mobility" which is the number of legal squares in a position, and "actual global mobility" which the the number of legal squares if you had unlimited moves (no captures) in a position.
Sounds interesting.
I wonder if there is a certain mathematical formula to calculate such a thing.
Unless it's a pawn or knight endgame, and in some other situations... then rook and knight pawns are much more valuable than center pawns heh.
Not sure where you get your information from. Rook/knight (and even bishop) pawns have drawing themes that other pawns simply do not have:
King vs rook pawn -- two drawing techniques, not present with any other pawn
King vs knight pawn -- one stalemate theme, not present with any other pawn
Knight plus rook pawn vs king -- two drawing themes, not present with any other pawn
Bishop plus wrong-colored-rook-pawn vs king -- a well known draw, not present with any other pawn
Rook plus pawn vs rook -- to quote Mueller "in rook endings a pawn at the edge is usually weaker than other pawns"
Queen vs pawn -- should be won unless it is a rook or bishop pawn, then there are drawing themes not present with any other pawn. To quote Mueller "a rook's or a bishop's pawn on the seventh rank draws against a queen if the attacking king is outside the winning zone"
I could go on. Of course everything depends on concrete calculation of specific positions, but in general it is easier to win with/harder to draw against central pawns, while the opposite is true of pawns near the edge...making them generally more desireable in an endgame, and therefore more valuable.
That's true, there are a number of technical endgame positions in books and... pretty much any I can think of involve better winning chances with center or bishop pawns or increase drawing ability for rook and knight pawns.
But in practical / complex endgames (many pawns) in a pure pawn endgame or knight endgame obviously the ability to create outside passers gives a big advantage. That's all I meant.
As for being advantageous, the knight pawn is the most versatile pawn for creating the rook vs queen fortress... for a bit of trivia