Ok,

In the middle and end game is it better to have your knights or bishops left

They should be the same, but I prefere 2 knights against 2 bishops anyday

Am I wrong, please advise

Yes, you're wrong.

Two Bishops are stronger than two Knights.

Two Bishops are stronger than 1 Knight and 1 Bishop.

So I should try to exchange off my knights for bishops thanks guys

General results mean so much in a given position, don't they? Although I guess if we mean the endgame to be a wide open position which it normally is, anyone would take 2 bishops to 2 knights, but more often than not you can force the trade of a set of minors where a single bishop v. knight is far from clear by any hard and fast principle.

Pawn structure dictates.

The OP posed good question that is very deep.  Not easy to answer, but easy to oversimplify and generalize.  If there is an answer to be found, it lies in understanding the particular pawn structure in which these pieces are being used.

There are many general guidelines that can serve as "place holders" for the brain as this question is still being asked by some of the top players and arguments about it have waged furiously for many years between some players.

When one gets to expert level and is ready for really deeper theory, works such as Timman's Power Chess With Pieces will provide deep insight into this vexing question.

I still know what I prefer in certain positions, but proving it is correct is another matter entirely.

 bishops are better in middle and endgame. But in the opening knights can make good forks.

 Also you can't make a checkmate with 2 knights

 but you can with 2 bishops

I like Bishops in the opening as well !

Actually one cam but it is not able to be forced.  It relies on opponent walking into it and "helpmating."

Interestingly, Two Knight & King v. King & Pawn can force checkmate.

You can look it up!

Knights working in tandem can be pretty lethal though!

two bishops can force mate, two knights cannot.

knights can still be very effective in middle game

 Yes, It's "situationally dependent"

its like this......close position,knights are stronger.....open position bishops are stronger......

4 or more pawns I go with 2 knights, 3 or less pawns I go with bishops, but then again, it all depends on the structure.

They confuse the heck out of me.  Just when i think I got them stymied with some deft pawn moves, the zig this way and zag that way and hone in in order to exploit the new weakness I've created.

Important to note that a single knight operates on both color squares so there is no hiding on a single color complex like a King can do v. a lone Bishop.

Also, because of this very fact, Zugzwang principles are not the same with a knight as with other pieces.  They cannot "lose a move" the way other pieces are able to.

On yet another level, there are some particulary amazing stalemates that the knight creates in endgames that are very hard to see coming and must really be known in order to find and execute.

Spoiler says "4 or more pawns I go with 2 knights, 3 or less pawns I go with bishops, but then again, it all depends on the structure."

This is great stuff guys, keep it coming.Thanks for all your comments

I like it when the horses have teeth. In one recent OTB encounter, they were grinning from beside the board as my clerics ran the opponent's king through all the tortures of the Inquisition.