How to know when it is time to trade down to an endgame? Sirs,

After considerable endgame study (i.e. Jeremy Silman's complete endgame course), I am finding that there is a wealth of information about how to win endgames.  However, I am noticing that there isn't as much information about knowing/judging when it is time to "trade down" to an endgame.

I'm not at all confused by the most basic principles such as "trade down to an endgame when you are a knight-ahead or better".  However, I would love to see an outline (or a link to some kind of equivalent knowledge) addressing more detailed situations such as:

--a.)  trading down to an endgame when white has two passed pawns on opposite sides of the board vs. black's poorly guarded pawn on the 7th rank.

--b.)  win/lose/draw analysis of bishop only endgames when bishop are of same color, or Knight vs. bishop endgame success?
etc, etc.

Does anyone know of a website, book, or resource addressing this niche subject of judging whether or not to trade down to an endgame?

Regards,

Brent
The reason there isn't much information on when to trade down when there isn't a large material advantage is because it is obvious.

If you have a small advantage but you calculate that trading down will leave you with an endgame which you know how to win then trade down. Note that even if you are bishop and knight up (say something like KQBN v KQ) and can trade down to a KBN v K endgame and you know that theoretically it is winning for you but you don't know how to win then there is no point in trading down because it is very easy for the defender to last 50 moves and claim the draw against someone who lacks the knowledge. Try and win some other way while there is more material on the board.

Similarly if you are a pawn or two down but have the chance to trade down to an opposite coloured bishop endgame where you know because of your endgame knowledge that your opponent's extra pawn(s) are not going to be enough for him because you know how to draw that position then trade down.

The difficult part is having the endgame knowledge in the first place.

If you reach a position where you are trying to decide whether to trade down or not but don't know, it is not because nobody has given you the magic answer. It is because you lack the endgame knowledge to judge the final position after the trade down.