Unstructured Comments on “The Relationship of Battle Damage to Unit Combat Performance”

Thanks to Russell1200 (see comments to Count of Opposing Forces | Mystics & Statistics (dupuyinstitute.org)), I now found out about a report “The Relationship of Battle Damage to Unit Combat Performance” by Leonard Wainstein of IDA prepared back in April 1986. Both the report and Wainstein are unknown to me.

The abstract of the report says

The purpose of this study is to investigate the historical basis for the assumption that a military formation will cease to be effective after having lost a pre-ordained percentage of its strength. Battles from the First World War to the 1982 Falklands campaign are reviewed for insight into the validity of this assumption.

The effect of heavy battte damage on units has been both variable and unpredictable. There is a relationship between losses and the continued willingness to fight, but it defies precise definition. So long as some men in the formation continue to fight as an organized entity, either in attack or defense, for whatever reason, the formation they represent cannot be termed ‘ineffective.”


My notes made while reading it:

  1. Page v: Contents: section on earlier studies references ORO report of 1954 (known to me… the Dorothy Clark report on Breakpoints) and an RAC report of 1966 (not known to me).
  2. Page 1: “The battle cases cited run from army level to battalion level, from single day engagements to those lasting several months” – my bias is to collect and analysis data based upon the same level of combat, i.e. division-level, battalion-level, etc.
  3. Page 1: Only 54 actions were examined (this seems small) and “only 11 represent cases where a formation collapsed, surrendered, was repulsed, was stalemated, or had to be taken out of the line after suffering some degree of damage.” (this seems like a really small sample).
  4. Page 2: “Colonel Trevor N. Dupuy, in describing the 1973 Middle East War, has written ‘The human element has always been important in war, and despite the technology available to both sides, the human element was undoubtedly the most significant feature in this war.’ The same comment could obviously be made about all the actions described in this paper.”
  5. Page 3: “There is no agreement among national armies, combat commanders, military historians or defense analysts as to the point when battle damage renders a formation impotent.”
  6.  Pages 1-5, Summary: This is worth reading in its entirety.
  7. Page 6: “The modeling community have developed a set of formulae for use in this determination, but it is not clear to what extent these formulae reflect actual battle experience.” (stated in 1986… pretty certain the “modeling community” has not taken significant corrective action).
  8. Page 8: Paragraph on perceived resistance is interesting.
  9. Pages 1-10: No mention of artillery.
  10. Page 11: “Despite the interest in and significance of the subject, relatively little research has been done across the years on casualty-effectiveness relationships.”
  11. Pages 11-12: Description of the Dorothy Clark 1954 ORO report, measuring 44 battalions. To quote Clark “the statement that a unit can be considered no longer combat effective when it has suffered a specific casualty percentage is a gross oversimplification not supported by combat data.”
  12. Pages 12-13: Description of Robert Best 1966 RAC report.
  13.  Page 23: Trevor Dupuy quoted again.
  14. Page 24: “Oriental fanaticism.”
  15. Page 44: HERO report from 1967 is referenced (HERO became TDI).
  16. Page 69: Trevor Dupuy is referenced.
  17. Page DL-2: A copy of this report went to CAA (Concepts Analysis Agency, now Center for Army Analysis).
  18. Page DL-3:  A copy went to HERO. I was there in 1987, do not recall seeing this report.

The IDA report is here: TheRelationshipBetweenBattleDamageAndCombatPerformance.


A few related past posts:

Count of Opposing Forces | Mystics & Statistics (dupuyinstitute.org)

Breakpoints | Mystics & Statistics (dupuyinstitute.org)

Historians and the Early Era of U.S. Army Operations Research | Mystics & Statistics (dupuyinstitute.org)

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Christopher A. Lawrence
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.
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.
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).
Mr. Lawrence lives in northern Virginia, near Washington, D.C., with his wife and son.

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  1. Only 54 actions were examined (this seems small) and “only 11 represent cases where a formation collapsed, surrendered, was repulsed, was stalemated, or had to be taken out of the line after suffering some degree of damage.” (this seems like a really small sample).

    Regarding the above statement about sample size, I’ll say that only 25 (some say 30) cases are needed in order to use “large-sample” statistical significance testing. That addresses the reliability issue concerning statistical conclusions, but the validity issue is a different matter (don’t know whether the study mixes apples and oranges and/or is based upon a solid theory-rationale). I’m guessing that there was some statistical analysis included in the report. There only being 11 cases of formation failure would be a problem if analyzing statistical differences between the 11 formations with regard to their degree/type of failing rather than if analyzing such differences between the 11 failing formations and the 43 non-failing formations. Still, I would feel less constrained when conducting such an analysis if there were at least 25 formation-failure cases and at least 25 non-failure cases (just so that I could use “large-sample” significance testing for statistical analysis of differences within each of the two formation conditions as well as differences between the two formation conditions).

    • This is why I keep saying need hundred of cases (and why I created databases with hundreds of cases). So he collected 54 cases and only 11 were actually usable. This is fairly typical of combat data. To get to your postulate target size of 30, then you are talking about 150 cases.

      But, in the Econometrics classes I took, 30 cases wasn’t the ideal, it was close to the minimum desired. People were really talking about 60 cases. So, 300+ cases needed.

      This is why I eventually grew our division-level data base to 752. Now I am armed to analyze Breakpoints. I have not done it yet. Will eventually become a chapter or two in More War by Numbers, when I get around to completing it.

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