Friday, December 28, 2012

4X4ing: Unit Strength Determination

This post continues on the 4X4 scenario idea. The topic is a method of determining the combat and defense ratings for the forces involved in a given historical scenario.

The premise of the post is that while I enjoy the rating system laid out in the Field of Battle rules, I’d like to apply something a little more “scientific” to the rating of the units involved in these scenarios. This is particularly true for scenarios where there is good muster data around the units involved.

I am going to state here that the goal is to rate a unit based upon its potential as an instrument of battle. The potential of the unit has these characteristics:

The armament of the unit
Field of Battle has a Musket and a Rifle category. My thought is that this adequately manages this aspect for me and this characteristic of a unit does not need to influence the ratings.

The size of the unit
The size of the unit is a big factor. The number of guns and bayonets that a unit can focus on the enemy is a valuable figure. A unit of 200 men will theoretically throw less lead than a unit of 400 men given similar conditions. In a pure weight of numbers match, the larger unit has an advantage in close combat power. Similarly, a larger unit could have more staying power reflected in the ability to sustain losses more efficiently than a smaller unit.

These are the premises which with to begin the ratings. These are simply the “cold and impersonal” numbers portion of the ratings. Upon these factors we will generate a “base rating” value for both combat and defense for each unit.

I don’t believe that there is any need to manipulate the Unit Integrity (UI) values of units in this modeling exercise. First of all, why worry about which unit has how many UI? Let’s just let UI be the measuring stick for the effectiveness of enemy action against the unit. The ratings of the units will properly influence the outcome of the die rolls by adjusting the size of the dice used.

The élan of the unit
Élan encompasses a lot of concepts. You could consider the training of a particular regiment. You could consider the past battlefield experiences to say that a unit is “veteran” or that it is “green”. What I am suggesting we consider – within the context of writing a wargame scenario around a slice of historical action – is this: the actual performance of the unit in the action itself.

Accounts of battle are loaded with the exploits of various units and their bravery under extreme stress. The opposite is also true, where units broke quickly even after only light casualties.

So, if the accounts of a battle call out particular units for their performance – for good or for ill – allow that to guide you in modifying either the combat or defense rating, or both, for those units.


So with that in mind, let’s look at some statistics. One of my favorite books is Regimental Strengths and Losses at Gettysburg. The amount of detail about the various units at the great battle is simply astounding. I’ll gladly let that guide my thoughts…

The armament of the unit
Of 238 Union infantry regiments present, 27 (11.3%) went into the Battle of Gettysburg at least partially armed with smooth bore muskets. Of these, 10 (4.2%) were seemingly fully equipped with smooth bore muskets.

A relatively accurate breakdown of Confederate infantry armament is seemingly not available for the Battle of Gettysburg. So, we’ll simply invent a workable estimate that is acceptable for war gaming the 1863 period. Let’s say that 30% of the infantry regiments and battalions would be at least partially equipped with smooth bore muskets and that 10% would be fully equipped with smooth-bore muskets. This is nearly three times the rate of the Army of the Potomac.

The size of the unit
The Army of the Potomac had 238 infantry regiments available for the Battle of Gettysburg while the Army of Northern Virginia had 170.

The average size for a regiment in the Army of the Potomac was 301 men. In the Army of Northern Virginia, the average infantry regiment size was 338 men. Generally speaking, for both armies at Gettysburg, the percentage of infantry units that were within approximately 50 men of the above numbers is about 30%.

So, I devised this chart with which to give my initial ratings values.

Strength         Combat Defense
250 or less D 8 D 4
251-350         D 10 D 6
351-450         D 10 D 8
451+ D 12 D 8

I think that this gives a good, basic representation of a unit’s theoretical effectiveness as an instrument of battle.

Let’s look at the forces involved on the Confederate side of the July 2nd Culp’s Hill action.

Steuart’s Brigade
                        Strength Combat    Defense
1 MD Bttn 424 D 10 D 8
1 NC 401 D 10 D 8
3 NC 582 D 12 D 8
10 VA 293 D 10 D 6
23 VA 266 D 10 D 6
37 VA 281 D 10 D 6

Williams’ Brigade
                        Strength Combat    Defense
1 LA 183 D 8 D 4
2 LA 251 D 10 D 6
10 LA 240 D 10 D 6
14 LA 298 D 10 D 6
15 LA 198 D 8 D 4

Jones’ Brigade
                        Strength Combat    Defense
21 VA 251 D 10 D 6
25 VA 297 D 10 D 6
42 VA 281 D 10 D 6
44 VA 241 D 10 D 6
48 VA 281 D 10 D 6
50 VA 254 D 10 D 6

The élan of the unit
Here is where we have a great opportunity for adjusting the values of various units. For the Confederate side, I have no read of any especially heroic or less-than-heroic acts by the units involved. I do know that the losses reported by the units involved were generally large. The First Maryland Battalion reported a 47% loss of men at Gettysburg. Some of these losses surely occurred on July 3rd but we can be safe in saying that the battalion participated in some pretty rough action. While I don't think that we can make a blanket statement that high losses indicates a stellar performance - we may be able to say that is certainly does not indicate a lack of willingness to engage the enemy.

So, for the Confederates, I’d be inclined just to leave the base ratings as they are. When we get to talking about the Union forces, we have some interesting conditions to consider. The 137th NY Volunteer Infantry seemingly performed very admirably, nearly in the same vein as the 20th Maine on the opposite end of the Union line. While the actions of the 137th NY are not as flamboyant as those of the 20th Maine, there is no doubt that their actions contributed heavily to saving this flank of the Union army. I am sure that we should consider upgrading their ratings to reflect this.

Also, several of Wadsworth’s units had been mauled on July 1st but still had a high fighting spirit. For example, the 7th Wisconsin began the great battle with 364 men and reported 48.9% losses during the three days. Let’s assume that most of those losses occurred on July 1st and theorize that the regiment has about 200 men available on July 2nd, purely hypothetical. This would, using our base rating system, give this regiment a Combat rating of “D8” and a Defense rating of “D4”. This is down considerably from a July 1st rating of “D10” and “D8” respectively. Given the reported “fight” that remained in the unit, maybe we should adjust the July 2nd rating back to a “D8” defense die. The quality and élan of the unit remains although they have fewer muskets.

Leadership at the regimental level is often a cause for these adjustments. Was the 20th Maine made up of men that were more superior to the men in other Union regiments? Unlikely. The unique combination of events, timing, and immediate leadership converged to create a superior result!

Lastly, we could always adjust the ratings for a unit that could be considered "elite" or "green". But, I think the performance of the unit on the field overrule this factor. How many green units stood and fought because they did not know when it was time to skedaddle? How many veteran units retired because they knew they could not win and the loss of life would be without gain? Our gaming notions of green and elite are not always aligned with events.

So, we should allow the history of a unit to modify the combat and defense ratings upwards or downwards as appropriate for a given scenario.

What If

Taken together, this provides us with good ground for “what if” variations on scenarios. What if the 1st Minnesota was a really crappy regiment on July 2nd? What if the 20th Maine was led by a less able man?

This is a whole different angle than “what if Hood had gone around the right” on July 2nd.


Next up, we’ll talk about Leadership ratings. My inclination is to lower overall Leadership to reflect the confusion of nightfall. This would result in a little less movement segments and more difficult rally actions. The trick is not to lower Leadership too much; the terrain will do some of that for us. Also, the Sequence Deck will be a great tool for modeling the Leadership difficulties.

I really enjoy the Field of Battle system, it gives us so many levers and switches we can pull to adjust circumstances!