A Bishop is stronger then a Knight !

TL;DR: there is no answer to whether bishops or knights are better in general. It all depends on the position. But positions in which the bishop is better occur more frequently than the reverse.

I just recently read the always insightful John Nunn on this very topic in his great Understanding Chess Middlegames book, and here's what he has to say:

In general, a bishop is worth slightly more than a knight or, to put it another way, positions that favour bishops tend to arise more often than those which favour knights. Bishops like open positions, especially those in which the center is free of pawns. Knights prefer blocked positions, especially those in which the center is congested with pawns. However, these rules of thumb have many exceptions....

The emphasis is mine. I thought that was an insightful way of thinking about the issue. In any given position, probably one of the bishop or the knight will be better than the other, and taking into account the sorts of positions that are commonly seen and their relative frequency, it is more commonly the case that some random position in a game will be better for a bishop than a knight.

This way of thinking about it makes it clear that there really isn't a general truth of which is better in the abstract, there are just the specific truths of which is better in each position, and it turns out that it's most commonly the bishop that is better. But we of course have to look at every position individually and consider the salient aspects of the position to determine which is better in any particular case. It's silly to say "the bishop is better" and use that as justification in some particular position without considering the position itself, because the truth of bishops being better is a truth about averages, and even if 50 out of 100 positions might be better for a bishop, it would still be silly to not consider the important features of a position, because the position could very well be one of the 35 out of 100 that the knight is better, or 1 of the 15 in which they are about equal (the exact numbers are unimportant, and I just made those up for illustration).

I like my way of putting it better.  But since nobody ever seemed to pay attention to it, I gave up on repeating myself (and took to being slightly resentful and waspish instead).

You mean your "A bishop is stronger, then a knight"? Or in a different threat?

No, that was merely a jape.  I came up with a formulation which I rather liked once upon a time (and in a different incarnation)...but nobody seemed to notice, so...

Knights are useful tools that you dispose of when once queens have been traded and the endgame is coming. (Putting down a horse)

Bishops get trapped and are to be traded for knights to disrupt pawn structure. (Giving a better endgame situation)

If you're going to keep telling us how great your formulation is, you should at least give us a link.

Okay, I will...from memory as best I can.  Actually, bishop and knight are as equal as two such disparate pieces can be (although their moves are not entirely dissimilar, since the knight's influence does describe little diagonal arcs).  It is a truism that bishops are favorable in open positions, whereas knights like for it to be closed.  That said, there are two reasons why positions tend to be better-suited to bishops:

1)  The game starts out wide-open.  Indeed, it takes quite a bit of doing to close it up, and the simple truth is that most chess positions are open.

2)  Closed positions tend to get clogged up (and drawish) more easily than open ones.  There is less play in them, and even though they may favor the knights, none of the other pieces will be well-served by such situations.  Then too at some point if you aim to win you're probably going to have to open up the position a bit, thus giving new life to the bishops (at least for a few moves).

Still, the importance of this open/closed dichotomy can be exaggerated.  One of the things I was surprised about in going through a collection of Spassky's games was how often he used a knight to advantage even in open positions (as long as he had a central outpost, he was doing fine).  And Karpov also seemed rather adept at handling the hoppers with open lines.

Both excellent points and compatible with Nunn. Your point 1 explains (in part) why bishop-favorable positions are more common. Your point 2 adds to that explanation for why bishop-favorable is more common and adds a nice extra nuance that explains why bishop-favorable positions are on average a bigger plus than knight-favorable positions are, which is an aspect that I hadn't thought of but seems correct to me.

I agree that open/closed dichotomy is exaggerated. The only accurate rule of thumb is to analyse each position carefully.

Thanks!  Maybe I won't have to go sulk in a corner as usual after all. 

Someone told me that a guy did an analysis and found that if you account for rating difference (the higher rated player usually had the bishop pair, being better at gaining this advantage), then 2 bishops vs two knights would only score about 53%.

It depends upon the situation.

Here Black's bishops is more powerful than knight.

The first one, Black's bishop is not that effective, while the second diagram; Black's bishop have advantage.

I would definitely say the forums help your chess playing if you read carefully. There are some people I read who have an excellent way of writing their ideas about chess, so I follow them. But there are also many people who have a great sentence or paragraph(or more) which is enlightening.

You're welcome

In the first diagram, if the turn belongs to white then the knights are stronger. Nb5--Nc6 fork Bishop and Rook also white has and advantage with 3 pawns vs 2 pawns on queen side.

 Also if white forces a trade with rooks then the d5 can be lost for black over a period of time. Yes the King would have to assist by protectind the d4 pawn. The 2 Knights then attack the d5 pawn. The threat of trying to turn the d4 pawn into a passed pawn using the knights might be enough to win the game.

Merry Christmas and have a Silent Knight.

I am a new chess player still learning but I find that knights are better at stumping and forking players than bishops skewing an opponent

Depends on the situation. A knight can be kept away by another knight easy and with help from other minor pieces. On same note same can be done to a Bishop. The trick is to create a situation where your knight or bishop can attack opponent and prevent your opponent from taking away the strenght of that piece.

You're absolutely right. I've never liked the Knight.  I think this piece has a dark and deceptive past. It is in the shape of an ugly brown cow for some mysterious reasons.