B+N vs 2N Endgame
The “Bishop+Knight vs Two Knights” endgame is a very complex and trappy endgame. A lot of these endgames will swap a pair of Knights to end up in a “Bishop vs Knight endgame”. Alternatively, a Bishop for Knight swap may occur, ending up in a “Knight endgame”.
But in some cases, all four of the pieces may remain without swaps. A lot will be riding on material issues such as which side has an extra pawn. Especially if one side has an outside passed pawn.