Bishop or Knight: Which is more valuable?

But if you have a bishop and a queen, even if the bishop is far away it can still help the queen attack.

But if you have a queen and a knight working together, with the knight defending the queen, the damage the combination can do will be giant.

Both can be said a equally powerful. Knight () can move in a L shape and most importantly can jump over pieces which other pieces apparently can't. Considering this advantage, we can say that knight is an essential piece. Bishop () on the other hand is more useful in checkmates and open positions as it allows us to move it diagonally forward or backwards. Considering this benefit, we can say it is a powerful peice. Even the strongest peice (queen ) has the quality of a bishop (and rook but excluding it as it's not related to this topic). So seeing these things, we can say both are major and prime pieces in chess. That is - 

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Sorry for spelling error -  *as

I saw a video a while back of Yasser Seirawan explaining why pieces have the material value they do. It's derived by counting the maximum number of squares a piece can control in your opponent's territory, divided by 2. 

A rook can control 10 squares, so its value is 5. A knight can control 6 squares, so its value is 3. A bishop can control 7 squares, so its value is 3.5. The only exception is the queen, because it is so useful at delivering perpetual checks - thus it gets boosted from a value of 8 (16 squares) to a 9. 

I personally think bishops are stronger because they lead up to more endgames rather than horses in most of the games that I play. Whilst trying to give a mate with a horse is more difficult.

It is correct that the relative strength of a knight and a bishop can depend on the dynamics of the position. In some positions, a bishop may be more powerful due to its ability to control long diagonals and target key squares, while in other positions a knight may be more effective due to its ability to jump over other pieces and control key outposts.

One example of how the strength of a bishop can be limited by the pawn structure is the scenario mentioned in the statement, where the opponent's bishops are tied up behind their own pawns. In this case, a knight that is able to occupy a strong outpost may be more powerful than the opponent's bishops.

The Chigorin Defense, 1.d4 d5 2.Nf3 Nc6 3.c4, is a good example of a situation where a bishop pair is traded for active play against passive bishops. In some lines of the Chigorin Defense, Black gives up their bishop pair in order to gain control of the center and create active play for their other pieces. This demonstrates that the relative strength of knights and bishops can depend on the specific position and the overall strategy of the player.

As I have learnt the values of chess peices, it was written that both knight () and Bishop () are given 3 points.

The bishop is regarded to be slightly more valuable than the knight, but I don't know what significance it yield when you can only play one game at a time.

The bishop reportedly has the statistics on his side, but as I said you can only play one game at a time.

It depends upon the pawns. When there aren't any, or at least few, the Bishop rule. When the pawns survive, particularly in "locked" formations, the Knights are all over that. The notion that Bishops are worth a bit more than Knights is because really, as the game goes on, how often are you in a situation where there are lots of pawns forming locked chains? When it's an open board it is probably better to have the Bishop (usually, yes, there are exceptions), but while it is closed, your Knights are probably worth more.

Google did some research using alphazero where they estimated the pawn value of the pieces a while back. You can read about it on page 16 of this paper - 2009.04374v2.pdf (arxiv.org)

But here were the results: 
Knight - 3.05
Bishop - 3.33
Rook - 5.63
Queen - 9.5

A little higher for the queen / rook than we thought. But going by this - if you have 2 bishops vs. 2 knights do you have a 0.56 advantage?

Conventional wisdom is bishops are better in open games and later in the game, knights are better in closed games and in midgames. I think bishops are also better when they can find a strong outpost where they're active but also allow you to focus on moving other pieces. But you always have to temper these evaluations by considering the position, and the pieces value in the position.

the bishop is 3.5 and the knight is only 3 so the bishop is better

Piece values are dynamic, and change depending on the position. Sometimes a knight is worth less than a pawn. Sometimes it's worth more than a rook ...

The same even goes for a pawn's value - it can change quite drastically, depending on what's happening on the board.

The "knight is worth 3" and the "bishop is worth 3.3" (or whatever value is assigned to it) is a rule of thumb - not an absolute. It's mostly for offering players a general idea of the current material value ... but positional and tactical considerations should always carry more weight.

G.K gave 3.15 for the bishop, whereas Fischer assigned 3.25 as face value.

Bishop = 3.2 ?

Perhaps much of this fraction is related to the pair of bishops. I mean Kaufmann said that an unpaired bishop is approximately equal to a knight within 1/50 margin, hence statistically insignificant.

pawn is 1 point, knight is 3, bishops are 3.5, rooks are 5, queen are 9.5

I would say the knight because people often don't see the move that I will use with it often