It requires a lot of investigation, but I can imagine that it can be extreme(ly?) profitable too. I'm working with 10 masterlevel problems with forced mate from Renko's ICT II. The solution of any given problem is a tree of 20 - 40 moves (moves of black and white counted as seperate moves) and all branches end in mate. The term forced means just that, the result will always be mate, with good and with bad defense.
Much to my surprise I noticed that all 150 moves of the attacker in all the 10 problems were checks! With no exceptions! So that will become part of the narrative. Of course there are forced mates imaginable that use non-checking moves too, but I'm already happy if my narrative covers 80% of all forced mates!
For the first move you have to find an invasion square where you can give check and where you have the upper hand. The immediate upper hand by attacking the square 4 times while it is defended 3 times, or the indirect upper hand after bringing forward new resources.
Most of the time the enemy king has escapesquares. You can think beforehand which piece will have to cover which escapesquare.
When the king is in check he has two possibilities. To flee or to move a piece. In the case he moves a piece, always be aware if no new escapesquare is created.
These are a few elements that I found and that can be used in a narrative which will cover al kinds of forced mates. I will give an example:
Black to move and mate.
- We know that the first move will be a check. There are 5 possible checks.
- There are two invasion squares where black has the upperhand: e4 and g4.
- At the moment there are 2 escapesquares for the white king: e2 and g3. e2 can be covered by the bishop or the queen, to assure future checks. g3 can be covered by Nf6.
- Since the knight on f6 already has a function for a future check on g3, the openingsmove must be done with the other knight: 1. . . . Ng4+
Besides an attempt to develop a high level narrative I try to find a good method to work my way through the tree of analysis. It looks logical to start with the most expensive variation first. In the above position is that when white takes with 2. fxg4. At that moment I have invested a knight, so that line must work. While if white not takes, the worst thing that can happen is to lose a tempo.
Investigation continued. . .