Below is a sample of what I have in mind.
For this example, the case is that only surface ships are in the sea areas, the weather is fine. the Axis has units only in the 4 Section box, and the Allies only have units in the 5 Section box.
Obviously things can get more complicated, but the actual code would take into account convoys, air units, unpleasant weather, section boxes included, etc.
Each cell in this table has a 1% chance of occurring.
What got me thinking about this was how often one side or the other gets 4+ surprise points. In this example, that occurs 25% of the time. If you measure the percentage as a function of at least one search roll succeeding, then it jumps to 25/70 = ~36%.
