which is better option to keep between knight or bishop ? (both sides are equal)

A general rule I have employed is that if a knight has a secure outpost and cannot be easily traded off then its point value increases by 1 for each rank it is on, until it passes the 6th and then its value decreases.  So a knight with a secure outpost on the 6th rank is worth more than a rook.  

In positions where a knight does not have a secure outpost you can estimate its value by its capacity to reach one, if it cannot reach a good square then it is not worth much.  

Also knights don't work well in pairs like bishops and rooks do (though for different reasons), so this counts against them when two knights are facing two other pieces.

If I simplify the answer then it would turn into something like: Most of the time Bishop but sometimes Knight, which doesn't really help when you not know which the times are that make the Knight stronger.

An outpost a position where a piece is defendes by a pawn and cannot be attacked by any piece that has less value then itself. The value of the outpost increases when there's no enemy pieces left that have the same value as the piece on the output.

Here's an example:

That is a terrible example. Both a5 (not right away) and Ne6 remove the White Knight. If I had to choose a side here I am taking Black every time, regardless of whos move it is.

Knights are better as they can jump

Here is a different example, a little over the top but it gives a nice visual example of an outpost.  Material is even but white is easily winning regardless of who has the move because of his super strong knight vs his opponents pathetic knight.

Again I prefer Black. I think Black may actually be winning by force in that diagram. White's King is just terrible, Black can play Rb4, Rcb8 and then the Knight is free to target c4 and will actually end up being more useful than White's knight which can only threaten f6 which is easily defended by the King.

OK now you're just talking crap, white is winning in that diagram regardless of who has the move.  If you don't believe me check it with an engine.

Kings are better

They can jump over peices

No other piece has this ability, whereas the queen can move diagonally too. So bishops aren't unique.

LOL I'm talking crap? Okay, White's Knight has to make 4 moves to get to e4 where it will finally be useful and by then c4 will be falling because White is a piece down as his King isn't playing.

Is everyone ignoring the fact that knights beat fishers?

I mean bishops

        For what it's worth, I'd point out that knights can reach all squares on the board and can jump other pieces, both friend and foe. Bishops can each only reach half of the squares and cannot jump other pieces, but they are only limited in range by other pieces. I think knights have it, always remembering the game position might dictate otherwise. I've had more success with knights, but that's just me.

OK looks like we'll have to actually resolve this.  Let's give black the move just to make it interesting.  

1...Rb4

2. Rxb4 cxb4

3. Ra1 and the black knight is toast

I ran an engine check on the position before I even posted it so you're not going to prove me wrong ;)

RG1951 wrote:

        For what it's worth, I'd point out that knights can reach all squares on the board and can jump other pieces, both friend and foe. Bishops can each only reach half of the squares and cannot jump other pieces, but they are only limited in range by other pieces. I think knights have it, always remembering the game position might dictate otherwise. I've had more success with knights, but that's just me.

Finally, someone speaking sense

For those wondering such as brumtown here is a position where bishops are clearly superior to knights.

Okay, Rb4 fails to a cute tactic. Instead, I play Kf7.

Yes, bishops are better in that position, but it is rare to be in a better position with a bishop than a knight. I will give a trophy to anyone who can show another position where bishops are better.

Good luck

Aw, bless <3.

The point is that none of black's plans will work because white has tactical responses to all of them due to the superior placement of his knight!  Do you not believe that I have engine checked this position?

1...Kf7 certainly drags it out longer but every single line leads to a white victory.

I don't understand what I am looking at, I have never used an engine. Tell you what, I'll challenge you to a game with this position. You can use an engine if you want. I want to see how White wins, it will be good for me.