Depth of a Hoplite phalanx

Very interesting Jim, and well worth a listen.

For what its worth, here is what Duncan Head in his “Armies of the Macedonian and Punic Wars” says:-
               “(Hoplites) most commonly fought in multiples of 4 ranks deep, usually eight, though four was known,
                 12 and 16 common. Asklepiodotus says early infantry organization was based on a file of eight men,
                 but there is little evidence that hoplites were organized at all down to this level, except in Sparta;
                 and Spartan organization was better adapted to depths of six or twelve, twelve being usual.”

Interestingly, MedievalThomas came up with a “House Rule” to allow Spears to gain +1 for side OR rear
support…but not both together (i.e. only count either one or the other).

This would allow a bit more freedom and variation in our Spear formations, as I very much doubt that
Anglo-Saxon ‘Select Fryd’ spearmen fought exactly 8 ranks deep, never more and never less.

It also helps to recreate certain historical battles more accurately, such as Marathon in 490 BC:-
   “Now, as they marshalled the host upon the field of Marathon, in order that the Athenian front might be of equal length with the Median, the ranks
     of the centre were diminished, and it became the weakest part of the line, while the wings were both made strong with a depth of many ranks.
     The two armies fought together on the plain of Marathon for a length of time, and in the mid battle, where the Persians themselves and the Sacae
     had their place, the barbarians were victorious and broke and pursued the Greeks into the inner country, but on the two wings the Athenians and
     the Plataeans defeated the enemy. Having so done, they suffered the routed barbarians to fly at their ease, and joining the two wings in one, fell
     upon those who had broken their own centre, and fought and conquered them.”
         (Source: www.thenagain.info/Classes/Sources/Herodotus-Marathon.html )

Having a small piece of rough going (where side and rear-support is not allowed) in the centre of the
Greek battleline nicely simulates this engagement.

Last of all, it helps us DBA wargamers to deploy historically.
On a normal 15 BW square table, you only have 7 BW of space to deploy heavy foot in.
Having the extra heavy foot behind the main battleline ends up looking more like a Roman formation
than a Greek one, with the troops deployed in multiple lines.
Allowing Spears to gain some sort of advantage for being in a column addresses this.