adonald wrote:Given the rather low probabilities you refer to form a group of steady squares (only 55% if drilled, 70% if veteran), it seems that this applies to infantry in line or open-half distance column. Otherwise, the probabilities you have are out of whack with the capabilities of some of those columns to form sqaure of just beat off a calavry attack.
Noting that it's 100% probability of forming square and that the 70% and 55% are the probabilities of the square being steady instead of disordered, I took a look at the probabilities of (1) the square being broken and (2) the attacking cavalry being spent.
Supposedly there were 2,500 French cavalry in the vicinity but not all would necessarily have attacked the square of the 2/5th and 77th Foot. Some would have been doing other tasks such as watching other parts of the British force including the British cavalry and the 21st Portuguese line that were a part of the retreating force. Some of it might even be considered as spent have having earlier lost a combat with the British cavalry (11th Light Dragoons and 1st Hussars). Presumably no artillery was able to fire at close range in concert with the cavalry attacks. The following link suggests that the artillery was used afterwards to harass and not in a combined arms effort.
http://www.historyofwar.org/articles/co ... bodon.html
So, I took the defending force to be a small, average veteran infantry unit, initially in tactical, that's attacked by a cavalry force, for which I used two cases (1) a small average veteran dragoon unit or (2) two small average veteran dragoon units.
The relevant outcomes are (a) the square is broken and (b) the cavalry is spent and therefore is significantly less able to impede the retreat of the infantry. If the square isn't broken, likely it will have lost cohesion but it should have a 70% chance (80% if the commander is charismatic) of recovering a level in the infantry's following turn.
The results are averaged over the CT results that the infantry forms a steady square or only forms a disordered square.
Case 1 (one attacking, unsupported cavalry unit):
Infantry Broken 3%
Cavalry unit spent 92%
Rules that allow 'fast' (as in faster than 1 MU) moving, steady squares (i.e., 100% chance the square is steady):
Infantry Broken 0.1%
Cavalry unit speand 94%
Case 2: (two attacking cavalry units - no support):
Infantry Broken 35%
At least one cavalry unit spent 92%
Both cavalry units spent 51%
Rule with moving, steady squares:
Infantry Broken 22%
At least one cavalry unit spent 94%
Both cavalry units spent 56%
Of course, there's the option of one attacking unit with one unit in support but I think the above illustrate the effects. The most significant factor is the number of attacking cavalry units. Presumably two attacking units is about right for the historical situation. There's mention of the real square being attacked on three sides but that's conceivable even with a single unit (brigade) of cavalry attacking and swarming around the square.
So, is the chance of Montbrun's cavalry breaking the square of the 2/5th and 77th 22% or 35%? Who knows. We don't have enough data to say what number is right or wrong. However, a 100% chance of a 'fast' moving square always being steady, even if it consisted of conscripts, doesn't seem right. Certainly not for conscripts.
That's just my opinion. I certainly don't expect to change any minds, but I thought, "well, those numbers are interesting".
ETA: I only saw Alistair's post above after I posted, so this wasn't in response to his post. If I had I might have included the case with 2 cavalry units attacking with 1 in support. I would represent the British cavalry as a small unit since it won it's earlier combat with one of Montbrun's columns. Possibly it was spent as a result of that combat but certainly one of Montbrun's units would have been spent. So the allocation of the French cavalry in this further case would be 1 unit to counter the British cavalry, 2 to attack and the spent unit in support. The odds change, of course, but it's still a reasonable possibility that the square isn't broken and that at least 1 further cavalry unit is spent. The artillery battery only came into play later on and it would seem from the total of 149 casualties suffered by the British for the entire affair that it would only have fired at medium range (in FoGN terms).
The main points of the exercise above, not doubt known to FoGN players are (1) it's risky for cavalry to attack good quality infantry from greater than 2 MU, (2) cavalry is fragile and easily spent and (3) an isolated unit that is ganged up on by 2 or more enemy units isn't likely to survive long but I don't think that's inconsistent with any other set of rules.