Value for the King?

Obviously worth a yak

But a yak moves like, and therefore is worth, a rook plus a knight because of its speed and agility.

Excellent point VULPES_VULPES! We may have to look into greek mythology to find a castle with the body of a horse in order to truly explain the worth of a yak/king-thing.

I thought it was Norse Mythology.

Yes, 4 isi a good estimate.  The strength of a piece is based on mobility, that's why.  Both knights and bishops hit a patchwork of squares, so it's hard to battle a king.

You can test this if you'd like and give one side an extra king so to speak that doesn't have the check rules applied to it and try to win some endgames.

The fact that it's slow and can't deal with pawns on both sides endgame for example isn't a factor in practical games because both sides always have a king.  So any deficiency in dealing with both wings is attributed to the difference in minor pieces (knight vs bishop for example)... but if you alter this for your test and give one side two pieces with the king's movement ability then test it without pawn on both sides :p  Have them fight a local battle.

I've asked alot of people and they say that the king has infinate value. Sorry if someone already said that

I don't know why books publish this... it's ridiculous.  I guess they think it's cute?  "You can't trade you king, har har har"

But giving the beginner something he can use to judge if trades are even or not is just a byproduct of the relative piece values.  The foundation of it speaks to the nature of all chess positions and would be a great teaching point.  The queen isn't more powerful because she can capture more at once.  A pawn can defender her attack as well as any piece can.  The value of a piece is based on its mobility... you can think of it as the likelihood it can find a useful job during the game.

And it's a good teaching point I believe because this is a key ingredient in many evaluations.  Does an attack work?  Well do you have more influence in that area?  i.e. more mobility.  If so, your attack is likely good.  Should I open the center?  Should I open a flank?  To know, notice whose pieces will get the better of it.  In the case of opening the center usually it's "have you finished your development?" (brought your pieces off the back rank).  In the case of a flank attack it's both pieces and space... which is where the axiom "attack where you pawn points" comes from... because that's where you have more space to maneuver... better chances then your opponent of finding useful squares for your pieces.

Also mobility is directly related to how the game ends.  When the king can't move and it's square is also attacked, then that ends the game.  Also why did grandmaster X sacrifice his rook?  Because mobility.  If it was in an attack it's because among the pieces left on the board his attackers are more influence than the left over defenders.

In the case of a positional sacrifice it's extended to the entire board.  The pieces left on have more influence than the opponent's do.  Not just locally as in an attack on the king, but overall.

I think when assigning a combat value of 4 to the King, people are not considering the fact that it can't be captured. It only has a value of 4 when it is treated entirely like a regular piece.

No, it's a practical consideration that's useful in real positions.  In an endgame it's more important to activate your king first over a minor piece, and more important that you activate a queen or rook than a king.  Choosing to enter into an endgame where your opponent's king is much closer to the center is almost always more dangerous than choosing to enter an endgame where your opponent has a well placed minor vs your knight on the rim so to speak.

As another example, in most cases involving blockading a passed pawn, it's better to have a minor piece preform the passive role than a king, and better for a king to take over this duty for a rook or queen.

Could be. I'm actually not very good at the origins of mythological creatures/chess pieces. Isn't a half-man/half-horse thing from Greek mythology?

Yeah a centaur.

Thanks Scottrf!

Not as irrelevant as the value of the king.

No... the "Value of the King" is the initial topic.

Well, if certain opinions are forbidden in your thread, then you should have stated this beforehand.

Their not forbidden. It's just that you really didn't give your own opinion.

I did. Maybe I wasn't clear enough, so I'll try again:

I really think that it doesn't make sense to assess a value to the king, because it's totally unclear what this value would mean, as long as you haven't given a procedure to use this value to evaluate a position.

Why wouldn't that qualify as my own opinion?

Sorry, I guess I misread your earlier posts then.

I just brought this topic up to assess a king-like piece, not the king itself, necessarily.

Fun discussions. Stuff like that.

I would much rather prefer an endgame with an active king and rook vs a cut off king with rook and knight, provided that my opponent's king is permanently cut off from the game, not being able to aid it's pawns in any form.So, judging by that strength, it's probably slightly better than a knight or a bishop, somewhere between 3 and 5. However, whether it's 3.5, 4 or  4.5 is a matter of personal preference.

All piece values are based on mobility.  The idea that you can use this to evaluate trades is secondary.  Therefore the fact that you can't trade you king is meaningless to assigning values to pieces.