Are the mathmatics of the situation= whichever piece has more available squares becomes the most effective. In an entirely closed postion the bishops lose a great deal of effectiveness bc pawns block their squares keeping the number of available squares to move few. Knights will never have more than 8 available squares ( the max of their movement), bishops can have at the most 13 available squares. Therefore, 4 bishops to 4 knights would have 20 more sqaures available to move. Making the bishops far more active. If you were a great player playing the knights, you would want to trade off two bishops of the same color giving your opponent a weak color all over the board.
I am not sure if I am correct but am curious how the analysis would work?
This is not the typical debate of which is worth more.
Quite by chance, my son came up with an interesting experiment to perhaps answer this question, or at least clarify it some. He asked, "What would it be like if one player had all four Knights, and the other had all four Bishops?"
I said I didn't know, so we tried it.
I figured in fairness, a good rule would be for one player to choose which pieces he wants, and other plays white to go first.
It was certainly an interesting game, and quite difficult for both sides. Has anyone ever tried this variation? If you're willing to give it a try, it would be interesting to read about your results and observations.