One way to provide real uncertainty is to use dummy markers or blinds to represent the real or suspected presence of forces not yet confirmed by the enemy.
I have played one game of this type -- I Ain't Been Shot Mum from Too Fat Lardies -- but only once. I do plan to test some of these ideas with Hearts of Tin the next time I have a chance to get out my SYW armies.
One observation is that the common images of blinds in Too Fat Lardies show fairly large sheets of paper more or less attractively displayed. Having though about the matter a bit, and looked at these lovely examples by Steven Thomas, I think that we can have a board with quite a few blinds on it without having it look like I accidentally spilled my paper crafts on the table.
So, purely on speculation, what do we need in the way of preconditions and rules to make blinds works (and I need a better name for them, too).
Well, we need to not actually know the enemy OB. If I know what forces the enemy starts with, eventually I will know if I have found them all, or how much I have to worry about them. To get the full effect of Mars-La-Tour on Bazaine, for example, you need the possibility to exist that in fact the whole German army is moving into his line of march. The latest version of Volley and Bayonet includes the Road to Glory subsystem for dealing with uncertain OB, and I will look at it in more detail in a later post.
To continue the uncertainty, I think you need to have some way to keep blinds in play. If they are not ugly, then as units -- or empty blinds -- are revealed there should be a way to bring them back. This could include splitting existing blinds into two, allowing units that have moved from sight to re-blind, and of course having blinds return on entry points as possible re-enforcements.
We need to decide what can be in a blind. Since the basic maneuver unit will be a division, clearly a blind can contain a division. It can also, of course, contain nothing. I suppose it should be able to contain detached cavalry regiments for doing recon (and what rules shall we have for detachments - something for another post).
We need rules for revealing blinds. Should all reveals be complete, or should I be able to reveal one stand (which may be all that is there) to force an enemy blind to reveal?
We need rules to keep unrevealed blinds out of sight of each other. Blinds should not be a free recon unit.
Not a huge list I think. Should be interesting.