Books and public sources that describe the QJM and TNDM

The QJM (Quantified Judgment Model) and TNDM (Tactical Numerical Deterministic Model are two combat models that Trevor Dupuy developed first in 1977 as the QJM, and then heavily revised and released in 1990 at the TNDM. We do sell a computerized version of the TNDM along with manuals and training courses but at a price out of reach for most individuals. See: TNDM & QJM – The Dupuy Institute

Now, I do regularly get enquiries about the model. The combat models are described in a half-dozen books.

1. The first version of the combat model, the QJM, is fully described in Trevor Dupuy’s book Numbers, Predictions and War (1977). You may have to fish around for it, it is not in print. I see a used version for sale on Amazon.com for $77.59 and $89.95.

2. The theoretical discussions that come from his work is described in his book Understanding War (1987). This is the most significant book written by Trevor Dupuy and should be in every serious military analyst’s library. Amazon.com has a used copy for $15.89. We have new copies for $24.95: Understanding War: History and Theory of Combat – The Dupuy Institute and Ordering Information – The Dupuy Institute. An earlier theoretical book, Evolution of Weapons and Warfare (1980) is available on Amazon.com for $19.96.

3. The new model, the TNDM, was created in 1990. It is described in two books, Attrition (1990) and If War Comes (1991). Both are out of print. Attrition is for sale on Amazon.com for $123.10. I tried to warn you: We our down to our last 16 copies of Attrition – The Dupuy Institute. If War Comes is not on Amazon.com (even though it was on the Times best-sellers list). His father’s books, written in 1938 is available for $15.55 paperback and $30.00 hardcover. Trevor Dupuy’s book is available on Ebay for $45.95.

4. Some quantitative analysis of combat and a little on the TNDM is described in my book War by Numbers (2017). That book is still in print and available in Amazon.com for $37.15 (list price 39.95). It is rated at 4.7 out of 5 on Amazon.

5. Now there were a lot of reports and studies does to develop these combat models. They include:

From 1962-1977: HERO Reports – The Dupuy Institute

From 1977-1984: HERO/TNDA Reports – The Dupuy Institute

From 1985-1990: HERO/DMSI Reports – The Dupuy Institute

From 1990-1992: TNDA Reports – The Dupuy Institute

From 1992 to present: TDI Reports – The Dupuy Institute

Ordering Information – The Dupuy Institute

6. There were also a dozen “International TNDM Newsletters” prepared when we were working various support contracts for the TNDM. They are here: TNDM Newsletter – The Dupuy Institute

7. Finally, it is discussed in our blog: Mystics & Statistics – The Dupuy Institute. Specifically if you search on our blog categories “TNDM”: TNDM – The Dupuy Institute or “Modeling, Simulation & Wargaming”: Modeling, Simulation & Wargaming – The Dupuy Institute or “casualty estimation”: Casualty estimation – The Dupuy Institute or “Dupuy’s Theory of Combat”: Dupuy’s Theory of Combat – The Dupuy Institute

8. Finally, it was discussed in our now inactive Forum: The Dupuy Institute Forum – powered by Infopop

Hopefully, that should answer a lot of enquiries.

Christopher A. Lawrence

Christopher A. Lawrence is a professional historian and military analyst. He is the Executive Director and President of The Dupuy Institute, an organization dedicated to scholarly research and objective analysis of historical data related to armed conflict and the resolution of armed conflict. The Dupuy Institute provides independent, historically-based analyses of lessons learned from modern military experience.
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Mr. Lawrence was the program manager for the Ardennes Campaign Simulation Data Base, the Kursk Data Base, the Modern Insurgency Spread Sheets and for a number of other smaller combat data bases. He has participated in casualty estimation studies (including estimates for Bosnia and Iraq) and studies of air campaign modeling, enemy prisoner of war capture rates, medium weight armor, urban warfare, situational awareness, counterinsurgency and other subjects for the U.S. Army, the Defense Department, the Joint Staff and the U.S. Air Force. He has also directed a number of studies related to the military impact of banning antipersonnel mines for the Joint Staff, Los Alamos National Laboratories and the Vietnam Veterans of American Foundation.
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His published works include papers and monographs for the Congressional Office of Technology Assessment and the Vietnam Veterans of American Foundation, in addition to over 40 articles written for limited-distribution newsletters and over 60 analytical reports prepared for the Defense Department. He is the author of Kursk: The Battle of Prokhorovka (Aberdeen Books, Sheridan, CO., 2015), America’s Modern Wars: Understanding Iraq, Afghanistan and Vietnam (Casemate Publishers, Philadelphia & Oxford, 2015), War by Numbers: Understanding Conventional Combat (Potomac Books, Lincoln, NE., 2017) , The Battle of Prokhorovka (Stackpole Books, Guilford, CT., 2019), The Battle for Kyiv (Frontline Books, Yorkshire, UK, 2023), Aces at Kursk (Air World, Yorkshire, UK, 2024), Hunting Falcon: The Story of WWI German Ace Hans-Joachim Buddecke (Air World, Yorkshire, UK, 2024) and The Siege of Mariupol (Frontline Books, Yorkshire, UK, 2024).
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Mr. Lawrence lives in northern Virginia, near Washington, D.C., with his wife and son.

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2 Comments

Joshua Foeller

February 28, 2025 / 9:04 am Reply

Is Attrition back in stock? The order page shows 53 copies available!?
- Christopher A. Lawrence
  
  February 28, 2025 / 10:34 am Reply
  
  Attrition is not back in stock and probably will not be for the next six months.
  
  53 copies was how many we had in 2015 when I first took inventory.
  
  I am thinking about re-printing it and have talked to the Dupuy family about it. But in the end, over nine years we sold 53 copies at $19.95. So $1K in gross sales. When things are quiet, I may do another print run, but right now trying to get another book finished.