Colonel Trevor N Dupuy and QJM

Who is Col. Trevor Dupuy and what is this QJM that I am hearing some of you ask?  Well in this blog will touch the very surface about those two later. 
But first off, if you remember two blog entries ago, I had done my answers for “Are you a real wargamer?” thread that has been floating around.  If you have done that same survey, give yourself a couple of extra points towards being a real wargamer if you already know who Dupuy is and what QJM means.

Next, why am I even discussing Dupuy and QJM on my blog?  Well, it ties back into even some earlier postings about me using maps, scaling out terrain boards, and battalion level wargaming for post-WWII (specifically for the Falklands.)  I had mention that there was a major shortage of post-WWII battalion level games (1 stand = 1 platoon and a player basically runs a battalion or two in a game), which I am assuming is due to the lack of the Cold War threat and modern day engagements tend to be company size actions, plus the raise in popularity for skirmish size games for modern (current day).  Really, the only battalion level system that I am aware of that is still in print for the post-WWII era is Cold War Commander.  One can also get a hold of Tacspiel, but that lacks the mechanics that most wargamers would want, even if I think it is a very well thought out game system.  But I also mention that there was another system that I found, but figured that most would not go for it.  I don’t even know if it has a proper name, but the system can be found in Clash of Arms’ Harpoon 4’s scenario book, South Atlantic War.  This book is the 2^nd edition scenario book for the Falklands War for the Harpoon naval game system.  The first edition was done by GDW before they went under and was designed to not only have scenarios for the air and sea combat using their Harpoon system, it also included scenarios for the land battles using their Combined Arms rules set, which was a battalion level, post-WWII miniature rules.  When GDW went away, so did Combined Arms.  I thought about trying to pick up a used copy of Combined Arms on the EBay, if it ever shows up, but it will really have to depend on the price. 

OK, here is the where we start tying Dupuy and QJM to what I was just talking about.  In the Clash of Arms’ 2^nd Edition for the South Atlantic War book, they had to create a set of ground combat rules for doing the land scenarios for the Falklands, since Combined Arms is no more and they do not have the rights to it.  So they created a system based off of Dupuy’s QJM with assistance of some of his colleagues.  The system is not a miniature rules set, but an area combat (you fight battles based off of specific squared off map areas (they are not necessary squares, but could be L shaped, etc.).  The rules also include information to do an early 1980’s US & USSR forces as well.  This sort of reminds me of Tacspiel or Peter Pig’s Square Bashing, I thought with some minor changes it could be converted to be more miniature like.  But, I don’t think that it will be worth the effort and will stick with Cold War Commander for now.  But I do realized that this was a neat idea and it will need a further look into again in the future for figuring out combat values for various units and campaign rules that you don’t want to game out in miniature.  So, I decided to take a little time to talk about Dupuy and his QJM, after I re-read his book.

Colonel Trevor N Dupuy was a graduate of West Point and served as an artillery officer in WWII.  He later went on to become a planner at the Pentagon and a military history professor at Harvard.  He wrote over 50 books on military history, including some which became required reading at West Point.  One of those books printed in the early 1980’s was, Numbers, Predictions, & War: The Use of History to Evaluate and Predict the Outcome of Armed Conflict.   It is in this book that Dupuy introduces the concept of Quantified Judgment Method of Analysis of Historical Combat Data (QJMA), which in turns creates the Quantified Judgment Model (QJM) for quantifying the military combat strength of a given force.  Through the QJM system, various mathematical formulas are used to predict the most likely winner of a battle.  According to several sources, this model was the most accurate of all the models to predict how the 1991 Desert Storm operation would end. 

Dupuy stated in another one of his books, Understanding War, that his idea for QJM comes from a gentleman that all TooFatLardie gamers have heard of before, Carl von Clausewitz.  Specifically, Dupuy uses Clausewitz’s theory, Law of Numbers, as his inspiration.  It was while creating various formulas and crunching numbers that he discovered that there was something else that was missing in the formulas.  That missing number was the human factor or training, morale, and commitment.  Not all troops are the same, even if they have are equipped the same.  It was this that got him into trouble among many historians and researchers.  Because again, and again, Dupuy’s formula’s showed that the average German unit was 20% in comparison to American or British forces.  In other words, 100 Germans normally had the same combat effectiveness as 120 Yanks or Tommies. Americans and Brits had a big issue with that.  They failed to realize that Dupuy showed that there were other factors that made things bad for the Germans and even if they had the effectiveness better than the Allies if all things were equal.  The other thing that should be noted was that Dupuy’s WWII data mostly came from the Italian campaign, which was a tough front.

I know that several big board game designers in the 1980’s used data from the QJMA/QJM to create the combat values for the various game pieces.  I don’t know if QJM has ever been accepted as an official model for the US Department of Defense or another nation, but Dupuy was trying to get the Egyptians to buy into it as well.

Now, I am not suggesting that everyone should read Numbers, Predictions, & War; it is a very dry, boring, and complex book to read and really would not be of much use to anyone except the most serious of researchers or someone that has a real interest in QJM and the math that is used to figure out the formulas.  It is very advance math for most, so take it as a warning.  It give just an example of one formula, this is the formula for creating a mobility factor that affects an attacking force:

m_a = M_a – (1-r_m x h_m)(M_a-1)

That is one of the easiest formulas! 

One of the more complex formulas is the following for Force Strength:

S = (W_a + W_mg + W_hw) x r_a + w_gi x r_u + (W_g + W_gy) (r_wg x h_wg x Z_wg x W_wg) + (W_i x r_wi x h_wi) + (W_y x r_wy x h_wy x Z_wy x W_yy)

Luckily, the rules in the Clash of Arms’ South Atlantic War the formulas have all been done, so there is only the Combat Effective Value (CEV) for every unit to plug into the random charts for combat effects based on terrain, weather, mobility, posture, etc.

But the book does have some interesting tidbits of information that I figure some would like to know.  One is that Dupuy determined that there are 73 different combat variables that affect combat.  These 73 variables are broken down into two main categories:  1) Variable Elements (hard numbers, # of troops, type of weapons, etc.) and 2) Variable Parameters (random conditions, weather, terrain, and human behavior.)  Between these two categories, there are a total of eleven sub-categories, including Weapon Effects, Terrain Factors, Posture Factors, etc. Some combat variables might fall under two or more of the sub-categories.  An example will be for the sub-category, “Terrain Factors”, Dupuy lists the following as combat variables: Mobility Effect, Defense Posture Effect, Infantry Weapons Effect, Artillery Effect, Air Effectiveness Effect, and Tank Effect.

One of the more interesting things that Dupuy address is in reviewing the historical data of battles is that he discovers that a numerically inferior attacking force generally wins the battle when comparing battles were the attacker is the victor (about 52% of the time).

If you are interested in knowing more about Dupuy or QJM, you can also visit their website here:  http://www.dupuyinstitute.org/

So, now that I scared a lot of you about the mechanics of creating the Combat Effective Value (CEV) for a unit using QJM, wouldn’t that mean that Clash of Arms’ Harpoon 4 Ground Combat System would be extremely complex?  No, actually it is very easy.  They summarized pretty much very thing for you.  Since this designed to be used for more of a board game, you move your forces by Combat Boxes (again, they are not always in the shape of squares, but specific regions or key points for battle.  The data that is provided in the scenario book allows you to customize your force by the man and weapon.  If one section/squad is missing 3 men, you can adjust the units Ground Combat Strength (GCS), which is the similar to what a CEV is, but only covers the Variable Elements for the unit.  The Variable Parameters are covered by using modifiers to the GCS.  But because this system is designed to reflect the GCS of a single man, you could use this same system for individual skirmish up to a Battalion size attack for the Falklands.

A quick example of how a combat is resolved, I am going to use for an example a platoon of 2 Para is doing a hasty attack on a well dug in platoon of Argentine conscripts from the 12^th Infantry Rgt in the rolling hills just west of the Darwin Settlement.  I am only allowing the Para’s to use a Hasty Attack since the Argentine platoon was unknown until it was spotted and they don’t have enough time to prepare for a Deliberate Attack (which there is rules for in the book).  I am giving the Para’s will use all 12 of their LAW’s to wrinkle out this position as Lt. Col. “H” Jones needs them to get moving.  Since the Argentine already saw the Para’s and open fired on them, the Para’s have no chance of getting a “Surprise” modifier.  The Argentines are not too keen on holding on to the end, so they will not get that modifier as well.  So let’s look at the numbers:

2 Para platoon:  GCS w/12 LAW’s (0.72) x Hasty Attack (1.00) = Final GCS or CEV is 0.72

Argentine platoon: GCS (0.1363) x Terrain (1.3) x Defensive posture (1.7) = CEV is 0.30

To figure out what to roll on the Combat Table, you divided your CEV by the opponent’s CEV to get a ratio.  So in the case of the Para’s, I would divide both numbers by 0.72, so my final ratio would be 1:0.42.  So I would look up that ratio or the closest to it on the Combat Table and roll for my damage to the Para’s by the Argentine platoon.  What is sort of neat about this is that the Argentine player doesn’t have a clue how much damage his force does to yours.  When the Argentine player does his rolls, he would divide both numbers by his CEV, so his ratio would be 1:2.4.  Needless to say, things will not look good for the Argentine platoon.

In the end, this is an interesting system, but it would not work for miniature gaming and there would be a large amount of paperwork to go with it.  I can see the value for this system when doing campaigns.

That is it for now

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Sapper