Data from the First Validation of the QJM

Christopher A. Lawrence
May 26, 2026

I do state in War by Numbers that there were three validations of the QJM/TNDM although the first was not published. That is not entirely correct. It was not published as a stand alone validation, but significant parts of it was published. The actual engagements were all published as part of the Combat Data Subscription Service. It was eight volumes, with the first volume published in 1975. In there it listed all the engagements used by the QJM. For example (page 6):

Now, the actual results of these test runs was published in his 1977 book Numbers, Predictions and War (NPW). As Trevor Dupuy specifically notes on page 58 of his book:

Appendix B contains a consolidated summary of HERO’s QJM Engagement Data Base. The first 8l examples in this consolidated statistical comparison show the theoretical results and actual results of these 81 World War II engagements (60 in the Development Data Base, 21 in the Validating Data Base; 61 in ltaly, 19 in northwest Europe, and 1 in Russia). In all of these the P/P value reflects an average German combat effectiveness superiority factor of about 23 percent.”

This was done back in the day when Data Base was two words and could exist on paper, vice a computer.

Anyhow, in Appendix B of NPW is “HERO’s QJM Data Base (as of May 1977)”. The specific engagement in question is given as:

No. Year & Date Battle Designation Force X Designation Posture

1. 1943, Sep 9-11 Port of Salerno B 46 ID A

Air %:

Force Y Designation Posture Na Nd S/S W W P/P

G 16 PzD PD 12,917 4,250 1.83 0 22 0.73

% cas/day

Surp P/P PR/PR CEV x y I I SE SE

1.5 1.10 0.87 0.79 3.51 0.94 7.4 2.3 1.02 3.85

I left out the subscripts. But one can see Appendix B (pages 234-235) for these details.

Now, this does not still actually do a direct validation in that it compares model results to actual historical combat results, but one can see the data they used for their inputs and what the outcomes were of these engagements.

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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