[archaeolept]

the proper mathematical measure would be amount of possible axes of advance ... ie. a combinatoric measure of the total number of shortest possible paths to, say, 5 provinces out. That would be the measure that would indicate how constrained a start is, or, conversely, how open the geographic situation. The number of possible paths will be much much less for black than for other teams.

the other measures are simple strategic ones. The situation is too narrow for both allies to support each other going one way or the other. i don't believe that is the case for anyone else. As well, the other simple strategic measure is the two vs 1 nature of the southern front. the mathematics on that one are simple enough to do on one hand, even after a gruesome industrial accident.