A long time ago (8 May 2002), on the old usenet group soc.history.what-if – David Flin posted this succinct summary of how to gauge troop quality – apologies for not posting a full usenet routing header, but usenet groups have seen their online archives collapse over the last 15 years.

As a rough rule of thumb, attacking requires about a 3-1 ratio of effectiveness. When troop and equipment quality is comparable, that comes down to a 3-1 ratio in numbers. It is harder to calculate when troop and equipment quality is not roughly equal (the most obvious example - to me, at any rate, is the Falklands Conflict of 1982. Troop qualities weren't approximately equal, with consequential effects). As a rough rule of thumb, it takes about 1 year to move large bodies of troops up 1 level of competence when in a war situation. Thus when forces are starting from scratch, you would expect the following progression: 0-1: Untrained militia. Capable of doing one thing at a time, very slowly. Liable to do unpredictable and unplanned actions at any time (fleeing in blind panic, massacring civilians out of hand, failing to carry out the most simple of tasks. Able to cover minimal distance of travel in one day. 1-2: Trained militia. Capable of doing one thing at a time effectively, or two things at a time slowly and with difficulty. Can sit tight and hold a position with some ease, but finds it much harder to both move and fight. Able to cover moderate distances of travel in one day. 2-3: Competent professional. Capable of doing two things at a time effectively (move and fight), and more than two things at a time with difficulty (conduct a fighting withdrawal). Can take simple positions effectively, but gets snagged up on complex defences (such as those defended by troops capable of counter-attacks). 3-4: Well-trained professional. 4+: War-weary professional. Capable of carrying out anything you want them to, but only too well aware of their own mortality, and well able to calculate the risk calculations. Likely to avoid putting themselves into harms way. We can see from WW1, and the British experience, that this applies. In 1914, Britain effectively used up its professional army. In 1915, it used up its reserves. In 1916, it was using 'Kitchener's Army', which was longer on pluck than on ability, and as a result, you had such events as the Somme. In 1917, the British army was better able to hold its own, although not without some problems. In 1918, it had reached the level of being able to carry out effective attacks. By 1920, it would have been worn out and unable to continue, only by this time, every one else would have also given up. If my analysis is correct, then we would expect to see the ACW [American Civil War] taking the following course (assuming that both sides start off with essentially a bunch of civilians whose main experience of war is what they've read about). 1861. Both sides fumble about making blunder after blunder. Any advance collapses under the weight of idiot militia doing inexplicable things. Any movement is pitifully slow and cumbersome, and achieving tactical surprise is about as plausible as expecting a politician to admit to having made a mistake. 1862. The more obvious blunders are now avoided. Any advance is still painfully slow and littered with blunders - troops are given lines of advance that cross, generals get seriously lost, troops rarely achieve time schedules that they are supposed to make. Advances get snagged up as soon as they hit major resistance, and suffer accordingly. 1863. Advances now are carried out more effectively, and can sometimes achieve tactical surprise. Attackers become more skilled at dealing with familiar defences, and adopt as a matter of course familiar routines. 1864. Troops are now capable of thinking for themselves, and can adapt to the unexpected. Defences need to be pretty darn effective in order to hold out. Of course, it is still easier to defend than attack, but the defender no longer has any margin for error. 1865. Troops are now starting to get cheesed off with the whole bloody affair, and are unlikely to get themselves killed in pointless assaults. The side in an untenable situation is going to appreciate just how untenable their situation is, and react accordingly (surrender, desert, mutiny, or just refuse to obey silly orders). If they look like they are on to a good thing, then fine. Otherwise, you've got a problem.

Second Front NOW – 1943 by Walter S. Dunn, Jr (published 1980) is a very informative book that goes deeply into the details on how both the US Army and German Army behaved in 1942-1943 when constructing a Division.

U.S. Army

From 1942 onwards, the US Army used a roughly standard format to raise a division.

First, a parent division for the new unit was designated. This unit would provide a cadre of 160 officers and 1200 enlisted (9.49% of a 14,316 man division) that would then be sent to schools or special training to prepare for their new assignment. A month before divisional activation, this cadre would be assembled and supplemented by 450 more officers. The “skeleton” of the division would then be formed – a usual skeleton was six officers and twelve men assigned to each company. On the official date of activation, about 13,400~ raw recruits would be sent to the new division, where their basic military training would commence two weeks after divisional activation.

After 17 weeks (3.9 months) of BMT for the raw recruits, the new division began three months of regimental unit training, followed by three months of divisional unit training, topped off by two months of combined arms training with tanks and aircraft. At the end of this nearly twelve month cycle, the US Division was considered combat ready and ready to engage in heavy offensive/defensive operations. One of the unusual features of the “Early Wave” divisions raised by the US was that many of them spent quite some time being trained – the 77th Infantry Division was activated in February 1942, but didn't depart for the battlefront until March 1944; after having been in training for nearly 26 months.

The typical US Division raised in 1942 also was used as cadre during 1942 to raise another division – this hurt as typically the best quality officers and NCOs were drained away, along with another thousand or so quality men sent to OCS (Officer Candidate School) during that period. Some divisions were unlucky enough to provide not one, but two cadres, which drained away 18.98% of total divisional strength, on top of OCS.

In reaction to the cadre issue disrupting divisional training, during late 1942, the US ended up designating two divisions as Replacement Pools to allow divisions to train without worrying about being used as cadre. These divisions were the 76th and 78th, and they served as replacement pools from October 1942 to March 1943, before resuming normal infantry training for overseas deployment.

German Army

By contrast with the US (and lesser British view) of standardized divisions trained to a uniform standard, the Germans utilized a high/low mix of divisions, where there would be mobile, semi-mobile and static divisions all being created at the same time to economize on manpower and equipment, but the biggest issue with their “low-mix” divisions was that they were constantly drained of manpower, especially if they were assigned to Western Europe.

For example, the German 65th Infantrie Division was formed in July 1942 using fresh recruits (Classes of 1922 and 1923) leavened with experienced men (33% of all men were prior combat wounded). Unfortunately for the unit in August 1942, it was ordered to surrender 6,993 out of 8,837 privates before being assigned to Coastal Defense duty in September 1942; followed by constant drains on manpower – exchanging a thousand fit men for nearly 600 men with frostbite, providing cadre for an infantry division destroyed at Stalingrad to be reformed, etc.

Based on the above examples, I believe the following Revised General Rules work quite well:

Revised General Rules for Troop Quality (based on Flin's Rules)

As a rule of thumb for large bodies of troops (i.e. battalion or larger), where you have to execute and coordinate combined arms operations to be successful, to move them up one level in general takes either:

Six months' of intense, concentrated training, either using live ammunition danger close with experienced trainers (Germany) or expensive fully mechanized maneuvers (US).

           OR

One year of moderate, low intensity training.

The various levels are:

1: Untrained: Capable of doing one thing at a time, very slowly. Liable to do unpredictable and unplanned actions at any time (fleeing in blind panic, massacring civilians out of hand, failing to carry out the most simple of tasks. Able to cover minimal distance of travel in one day.

2: Trained: Capable of doing one thing at a time effectively, or two things at a time slowly and with difficulty. Can sit tight and hold a position with some ease, but finds it much harder to both move and fight. Able to cover moderate distances of travel in one day.

3: Competent. Capable of doing two things at a time effectively (move and fight), and more than two things at a time with difficulty (conduct a fighting withdrawal). Can take simple positions effectively, but gets snagged up on complex defenses (such as those defended by troops capable of counter-attacks).

4: Professional. Capable of carrying out any mission assigned to them. Consider combat “no worse” than maneuvers (the view of many men in the US 85th and 88th Infantry Divisions in Italy).

Units are capable of going down in the rankings due to losses, whether from battle casualties or through being ordered to provide cadres for new units.

I think a good rule of thumb is for every 10% of total manpower lost, whether combat losses or paper losses, deduct one skill level.

This loss in skill level can be regained at the rate of 3 months' intense or 6 months' moderate training; representing the fact that a “core” of trained personnel exist and can bring the “new guys” mostly up to speed, rather than them all having to figure it out for themselves. This “bonus” to retraining can however be lost, if the unit suffers 20-30% casualties – because in large scale formations; most of the “unit slice” is in support/logistics units, rather than the actual trigger pullers who are a small minority – thus heavy casualties can quickly decimate the combat troops out of proportion to their basis of the “unit slice”.

SPECIAL TAGS:

War-Weary – The unit is composed mainly of experienced men (or experienced battalion commanders) who have been under sustained combat. They're quite experienced, but also quite aware of their own mortality and will avoid or creatively interpret orders that they view as placing themselves in harms' way unnecessarily. Because of their experience, the unit can “upskill” faster, but at the same time, it's also more brittle in combat; if that makes sense.

Applying This Rule

A good test of this set of rule(s) is the current 2022+ Russo-Ukrainian War. If you apply them, it explains a lot about the performance of both sides' units – brand new units composed of draftees with a leavening of prior service personnel are being thrown into combat with <1 year of training, so they can defend, but can't perform complex combined arms assaults on either side.

Likewise, for the units that have been given intense training before being committed to combat (Ukrainian units equipped with modern western kit), they suffer enough casualties from the mass use of FPV drones, artillery, etc to force the unit(s) to be pulled back for retraining as the trained people keep getting killed.