Every so often I decide to sacrifice a bishop early in the game to prevent the opponent from castling. The opponent's only move out of check is to capture. Has anyone figured out relatively what that's worth? Obviously position matters but my question is, "is it worth it giving up a bishop or a knight in order to prevent castling?"

Probably about half a pawn, position dependant of course. Almost never worth sacrificing on f7 for.

Yeah, that early there are too many posibilities to just give up that bishop

The entire point system is bogus.  The Knight = 3, Rook = 5, etc crap more has to do with if there is absolutely nothing else on the board, what their value is.  With Kings and a bunch of other pieces on the board, there are numerous times that taking a Bishop or Knight and giving up your Rook for it is totally correct, especially if there are no open files.

That said, just throwing away a piece to avoid the opponent from Castling and no other reason is a complete and utter joke.  How many "points"?  Maybe 0.02 tops!  I've had numerous games that I've won without castling.

This whole thread is a complete joke!

@ThrillerFan no need to be rude. Nothing wrong with intellectual curiousity, my friend.

He's exaggerating for effect, but maybe that is the best way of getting the point across to you. Sacrificing with no reason other than to stop your opponent from castling (with no follow up attack available) is terrible play. The only reason I said as high as half a pawn is because sometimes there is a follow up attack.

The question is revealing. As chess players we have to analyse and so "work" at the game. Experience teaches us that it is often useful to work off generalisations such as : Don't move a piece twice in the opening, castle as soon as possible, don't make too many pawn moves and so on...

As average to good players many of us have experience playing a novice who realises our strength and tries very hard to analyse the position after two moves, say 1e4 and e5. This isn't a position for analysis. 

Chess is a balance between generalisation and analysis. Knowing when to analyse deeply or not is the question. Experience may tell us. Even though every player who wants to improve will work hard, we still want "The Get Rich Quick" fix. We want to bring a bag load of generalisations to the board to avoid working. We assign values to pieces, say a pawn is worth three tempi and so on.

Chess is in part governed by generalisations and in part governed by exceptions. Exceptional players can make the necessary call. That is why they are excpetional players !

To use the Qxd8+ early trade of queens as the example, at most about a half-pawn, all else being equal, though all else never is equal.

How many points is eliminating the ability to castle worth?

Well if you are sac-ing a bishop on f7.

Than you are giving up a bishop which is valued at 3 points.

To gain only a pawn which is valued at 1 point.

Thus, the difference would be 2 points.

It is costing you -2.0  to eliminate your opponents castling rights by doing an unsound sac of course!

What? No ****. What do you think this is? Teaching maths to your infant? The question is what additional damage is caused by the inability to castle. Not: What is 3-1?

Well from where I am sitting the answer to your question in red is Yes!

Apparently I am teaching math to infants because your still asking the same dumb question to me.

You can't add collateral damage with out a position sherlock!

All you can do is use the generic values of each piece as a rough guide!

1 Bishop = 3 points

subtracting

1 Pawn = 1 point

Your answer is 2!

This is your generic answer with out a position!

TA DA!

I've got no time for you.

I completely disagree - losing the right to castle is worse than losing a queen - I always resign at that point

Castling is over-rated.

There are perfectly respectable opening systems in which one player or the other forfeits castling rights for a reason that you would probably find rather trivial... to avoid an exchange of pieces, for example.

there are people who think that castling is more than a queen?

black is easily winning there

If you lose a queen - the board wouldn't look like that

It depends, maybe if the king is wide open and your pieces can attack the king, it maybe is better to sac, since 1: the king is in the middle and 2: its much easier to attack. I like le fegatello for that same reason. You sac a piece for the king to go to the center (then you get the piece back) and you play very aggresively

As you can see, the king is wide open and you'll get the piece back. in that case, it is very good (chess.com calls it brilliant) to sac it for the king to be wide open. Be careful tho, sometimes your opponent will try to manually castle;

As you can see, the black pieces manually castle and you are simply down a piece for a pawn.

A queen trade, apparently.