Category Research & Analysis

Two missing reports – #26 and #27

As I was going through our early reports, it again came to my attention that we were missing two early reports. See: TDI – The Dupuy Institute Publications. They are:

26. Target/Range Experience for Tank & Antitank Weapons (1969) (Batelle) – Pages: NA

27. Historical Data on Tactical Air Operations: The Rome Campaign, 11 May-17 June 1944 (1970) (AFS&A) – Pages: NA

They have been missing for a while. Our report list comes from the 1980s, and even then their pages were listed as “N/A.” I gather that means we were missing them at that time. They may have been classified. When DMSi/HERO was shut down in the early 1990s, any classified reports had to be burned.

Anyhow, the customers for those reports were Batelle and AFS&A. If anyone has access to these reports, we would love to get a copy for our files.

Personnel Attrition Rates….

While searching the internet for something else, I ran across this April 1996 report by Dr. Robert L. Helmbold of CAA (Center for Army Analysis). Personnel Attrition Rates in Historical Land Combat Operations: Losses of National Populations, Armed Forces, Army Groups, and Lower Level Land Combat Forces. (

I am surprised that I have not seen that before. At the time of its publication we were under contract with CAA for work on the Kursk Data Base (KDB). I gather Dr. Helmbold retired shortly thereafter. I was asked if I wanted to take over his slot at CAA, but being the executive officer of TDI, I was not willing to step back down to a non-management position. I had gotten spoilt.

Anyhow, a few notes:

Page 1-1 (page 22 in the pdf file): They list six supporting reports done between 1992-1995. I assume there are all available from DTIC.

Page 2-1 (page 27): This chapter addresses the question of losses in wars as a whole. This might have some value in looking at mobilization levels for Ukraine.

Page 3-1 (page 55): This chapter addresses variation of loses by nationality, theater and major operations or campaigns.

Page 4-1 (page 66): The Chapter addresses losses by Army Groups. This chapter is mostly based upon George Kuhn’s work the LMI, as is some of the next two chapters. Some of George Kuhn’s data was collected under contract with HERO (our predecessor company).

Page 5-1 (page 75): This chapter address losses by Army. This chapter does include a number of graphs from the CDB90 data base (which was built from our work) as does the next chapter.

Page 6-1 (page 99): This chapter addresses losses by Corps.

Anyhow, two Dupuy books are referenced in this report, along with four HERO reports. In the study directive the Ardennes Campaign Simulation Data Base (ACSDB) and the Kursk Data Base (KDB) was both referenced but they were not used. I was the program manager for both of those databases.

The 40% Rule

Hadn’t done a blog post in the while. Been focused on getting a book done. Sorry.

There is a rule of thumb often quoted out there and often put in war games that a unit becomes ineffective or reaches a breakpoint at 40% casualties. The basis for this rule is a very limited body of studies and analysis.

First, I have never seen a study on when a unit become ineffective. Even though it is now an accepted discussion point, I have not seen such a study establishing this relationship and do not think that such a study exists. I am not saying that there is not a relationship between casualties and unit effectiveness, what I am saying that I have never seen a study establishing that 1) this relationship exists, and 2) what are its measurements, and 3) what is the degree of degradation.

What has been done is studies on breakpoints, and over time, a rule of thumb that at 40% a unit “breaks” appears to be widely accepted. It appears that this rule has then been transferred to measuring unit effectiveness.

The starting point for “breakpoints” study is Dorothy Clark’s study of 43 battalions from World War II done in 1954. That study showed that the average casualties for these battalions was around 40%, although the ranged from around 1% to near 100%. Her conclusion was that “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.” She also stated “Because of wide variations in data, average loss percentages alone have limited meaning.”. We have discussed this before, see: C-WAM 4 (Breakpoints) | Mystics & Statistics ( and April | 2018 | Mystics & Statistics ( and Breakpoints in U.S. Army Doctrine | Mystics & Statistics ( and Response 3 (Breakpoints) | Mystics & Statistics (

The next point is the U.S. Army’s Maneuver Control manuals (FM 105-5) which in 1964 set the attacker’s breakpoint at around 20 percent casualties and the defender’s breakpoint at around 40 percent at the battalion-level. Charts in the 1964 Maneuver Control field manual showed a curve with the probability of unit break based on percentage of combat casualties. Once a defending unit reached around 40 percent casualties, the chance of breaking approached 100 percent. Once an attacking unit reached around 20 percent casualties, the chance of its halting (type I break) approached 100 percent, and the chance of its breaking (type II break) reached 40 percent. These data were for battalion-level combat. 

We have never found any studies establishing the data for these Maneuver Control manuals and we do not think they exist. Something may have been assembled when they were writing these manuals, but we have not been able to find any such files. Most likely, the tables were extension of the Dorothy Clark study, even though she said that it should not apply.

Anyhow, that is kind of it. Other stuff had been published on breakpoints, Helmbold in 1972, McQuie in 1987 (see: Battle Outcomes: Casualty Rates As a Measure of Defeat | Mystics & Statistics ( and Dupuy in the late 1980s, but I have not seen anything of significance since, as it appears that most significant studies and analysis work stopped around 1989. 

Now, Dr. Richard Harrison, who spends a lot of time translating old Soviet documents, has just sent me this: 

“Supposing that for the entire month not a single unit will receive reinforcements, then we will have a weakening of 30%, with 70% of the troops present. This is a significant weakening, but it does not yet deprive the unit of its combat strength; the latter’s fall begins approximately with losses of 40%.”

His source is: 

N.N. Movchin, Posledovatel’nye Operatsii po Opytu Marny i Visly (Consecutive Operations on the Experience of the Marne and Vistula) (Moscow and Leningrad: Gosudarstvennoe Izdatel’stvo, 1928), page 99.

So, the U.S. came up with the 40% rule in 1954 which it disowned and then adopted in 1964 regardless. And here we have a 1928 Russian writing which is directly applying a 40% rule to unit effectiveness. I have no idea what the analytical basis is for that statement, but it does get my attention.  

Encyclopedia of Military History

Long before the internet, people used to write (and read) encyclopedias. I still have a few in my house, including a Funk & Wagnalls (as in “look that up in your Funk & Wagnalls”). Just saw a twitter post yesterday that referenced Dupuy & Dupuy’s Encyclopedia of Military History: Paul Poast on X: “To identify war outcomes, Stam’s study drew on military histories, notably the encyclopedic volume by Dupuy & Dupuy (cc @dupuyinstitute).” / X (

This was apparently part of a thread Dr. Paul Poast had on coding victories. As he notes, in a “pioneering work on war outcomes by Alan Stam” (Paul Poast on X: “This can be seen by considering the pioneering work on war outcomes by Alan Stam.” / X (, he drew heavily on Dupuy & Dupuy’s Encyclopedia of Military History. Now, that is gratifying. I am not familiar with Allan C. Stam and his work. In fact, this is the first I have heard of it (I do not get out much). It was first published in 1996. But, as they are referencing Trevor Dupuy’s work, I figured I should at least mention it in a blog post.

Interesting review of The Battle for Kyiv

Just stumbled last night across this review of The Battle for Kyiv. It is an interesting take on the subject. The reviewer is someone I know.

Draft history in The Battle of Kyiv: The Fight for Ukraine’s Capital by Christopher A. Lawrence – Armchair Dragoons

Now, my nagging suspicion is that it will be a while (decades) before anything other than a “draft” history can be written. Might be more than a few decades to get access to Russian archives. We were not able to get access to Soviet archives on Kursk (1943) until 1993, and that was only by using some round about means and a project budget not available to most historians. We have still not gotten access to Chinese records from the Korea War (1950–1953). So, one is certainly looking at least at 50 to 75 years in these cases.

Measuring Unit Effectiveness in Italy

We are in discussion over revisiting the measurement of combat effectiveness of select units in Italy 1943-1945. This was done by Trevor Dupuy in Numbers, Predictions and Wars (1977) by division using the QJM (Quantified Judgment Model) and was done in aggregate by me in War by Numbers (2017) using simply comparative statistics. If you feel lifeless reading blogs like this, you can rest for a bit through sites such as 홈카지노.

For a little background on page 115 of Understanding War is a chart of German, UK and U.S. units in the Italian Campaign and their CEVs (Combat Effectiveness Values). Their values range from 0.60 to 1.49. The German Hermann Goering Division is the highest rated division at 1.49. This is based upon five engagements. The German 3rd PzGrD was rated 1.17 based upon 17 engagements and 15th PzGrD was rated 1.12 based upon 11 engagements. This was done using the QJM.
    For reference, I would recommend reading the following four books:
1. Understanding War
2. War by Numbers
3. Attrition (optional)
4. Numbers, Predictions and War (optional)
There are two ways to measure combat effectiveness. 1) Do a model run and compared the results of the model run to historical data. This requires 1) a historically validated combat model (there are very few), and 2) confidence in the model. 2) The other option is to do a statistical comparison of a large number of engagements. This is what I did in Chapters 5, 6 and 7 of War by Numbers.
One can measure combat effectiveness by three means: 1) Casualty effectiveness, 2) special effectiveness (distance opposed advance) or 3) Mission effectiveness. This is all discussed in Trevor Dupuy’s work and in War by Numbers.
To date, the only people I am aware of who have published their analysis of combat effectiveness is Trevor Dupuy, me (Chris Lawrence) and Niklas Zetterling. See: CEV Calculations in Italy, 1943 | Mystics & Statistics ( and his book Normandy 1944 (recently revised and republished). There is also a six-volume quantitative effort related to Operation Barbarossa by Nigel Askey, which I have never looked at. Everyone else has ignored quantifying this issue, although there are no shortage of people claiming units are good, bad or elite. How they determine this is judgment (and it is often uncertain as to what the basis is for this judgment).
Now, the original work on this was done by Trevor Dupuy in the late 1970s based upon his data collection and the QJM. Since that time the model has been updated to the TNDM. The engagements used for the QJM validation were then simplified (especially in weapons counts) and assembled into the LWDB (Land Warfare Data Base). The LWDB had around 70 engagements from the Italian Campaign. Since that time we have created the DuWar series of databases which includes the DLEDB (Division-Level Engagement Data Base). See: The History of the DuWar Data Bases | Mystics & Statistics ( We have doubled the number of Italian Campaign engagements to around 140.
There are a total of 141 Italian Campaign division-level engagements in the DLEDB. The first 140 engagements cover from September 1943 to early June 1944. There is almost 12 months of war not covered and not all units in the first part of the campaign are covered. With all the various nationalities involved (i.e German, Italian, U.S., UK, Free French, Moroccan, New Zealand, South African, Poland, Indian, Canadian, Brazilian, Greek, etc.), the Italian Campaign is a fertile field for this work. We are looking at stepping back into this. 
Units involved in engagements in the DELDB:
3rd PzGrD: 25 cases
15th PzGrD: 39 cases
16th PzD: 7 cases
26th PzD: 8 cases
29 PzGrD: 6 cases
65th ID: 5 cases
94th ID: 8 cases
305th ID: 4 cases
362nd ID: 3 cases
715th ID: 2 cases
4th Para D: 3 cases
HG PzGrD: 26 cases
LXXVI Pz Corps: 4 cases
12th Para Rgt: 1 case
1st AD: 3 cases
3rd ID: 19 cases
34th ID: 15 cases
36th ID: 12 cases
45th ID: 20 cases
85th ID: 7 cases
88th ID: 4 cases
509th PIB: 1 case
1st SSF: 1 case
7th AD: 6 cases
1st ID: 9 cases
5th ID: 2 cases
46th ID: 18 cases
56th ID: 24 cases

Top Ten Blog posts in 2023

Happy New Year to all. 2023 is over. Not the best year for many in the world. Wanted to take a moment to list out our top ten blog posts for 2023 (based upon number of hits). They are:

  1. Wounded-to-killed ratios in Ukraine in 2022 | Mystics & Statistics (
  2. U.S. Tank Losses and Crew Casualties in World War II | Mystics & Statistics ( – a blog post by Dr. Shawn Woodford from 2016.
  3. How many brigades did Ukraine start with war with? | Mystics & Statistics ( – this is actually clipped from my book The Battle for Kyiv.
  4. Population over Time (US vs USSR) | Mystics & Statistics ( – a blog post from 2018. I suspect this gets so many hits because this was the initial entry point for a number of people who periodically check on this blog and they continue to use this post to direct them to our blog.
  5. German versus Soviet Artillery at Kursk | Mystics & Statistics ( – another 2018 blog post.
  6. New WWII German Maps At The National Archives | Mystics & Statistics ( – a 2017 blog post by Dr. Shawn Woodford.
  7. How Does the U.S. Army Calculate Combat Power? ¯\_(ツ)_/¯ | Mystics & Statistics ( – another 2017 blog post by Dr. Shawn Woodford.
  8. Tank Loss Rates in Combat: Then and Now | Mystics & Statistics ( – a 2016 blog post by Dr. Shawn Woodford.
  9. U.S. Army Force Ratios | Mystics & Statistics ( – a 2018 blog post.
  10. The Russian Artillery Strike That Spooked The U.S. Army | Mystics & Statistics ( – a 2017 blog post by Dr. Shawn Woodford. It was the second most popular blog post in 2022.

Honorable mentions:

13. Wounded-To-Killed Ratios | Mystics & Statistics ( – this 2016 blog post was our most popular blog post in 2022.

16. Where Did Japan Go? | Mystics & Statistics ( – this 2018 blog post was sort of the culmination of our series of demographic blog posts. May revisit this subject again this year.

18. The Russo-Ukrainian War – Day 560 | Mystics & Statistics ( – for a while we did post daily (then two-three times a week) about the war in Ukraine. This was our most popular one of those posts. We will probably restart these again sometime this winter, like when there is a danger of the front lines again moving.


Anyhow, the blog has been quieter for the last three months. This was in part because I was on travel and in part because I needed to finish up a book (The Siege of Mariupol). To date, I have not learned how to multi-task and complete a book, so the book has had the priority. Sorry to anyone I have not responded to as a result.

The Battle for Kyiv book will be available in the U.S. on come 18 January 2024.

Current book release schedule

I have four books in process or about to be released. They are:

The Battle for Kyiv:
– UK release date: 28 November
– U.S. release date: 18 January 2024

Aces at Kursk:
– UK release date: 30 January 2024
– U.S. release date: posted as 18 January 2024, but suspect release date will be in March 2024.

Hunting Falcon:
– UK release date: 28 February 2024
– U.S. release date: posted as 29 February 2024, but suspect released date will be in April 2024.

The Siege of Mariupol:
– UK release date: sometime in 2024
– U.S. release date: sometime in 2024

Books under consideration for 2024/2025:
The Battle for the Donbas
The Battle of Tolstoye Woods (from the Battle of Kursk)
More War by Numbers

We our down to our last 16 copies of Attrition

Just to give you all a heads-up, we are down to our last 16 copies of Attrition: Forecasting Battle Casualties and Equipment Losses in Modern War. Hard to predict how long those remaining copies will last. It is still affordable at $19.95. Right now, Amazon is selling it used for $50 – $400. See: TDI Books For Sale (

I do not control the rights to reprint it.

Ordering info is here: TDI Purchasing Publications (


Third video posted to our YouTube site

We have now published the third video from the first Historical Analysis Annual Conference (HAAC) to our YouTube site. It is here: (1) Data for Wargames: Lawrence – YouTube

The briefing in this third video goes for most of the video, as discussion and comments were made mostly during the briefing. The briefing ends at 55:30 the video ends at 59:27.

A few discussions of note:

At 10:10 – A discussion of what TDI does

At 18:52 – A discussion of Breakpoints

At 32:54 – A discussion of Suppression

At 37:18 – A discussion of what we don’t know

There were some issues with sound from virtual attendees, but one of these was Robert Helmbold, so, please bear with us.

The viewgraphs for these briefings were previous posted here: Presentations from HAAC – Data for Wargames | Mystics & Statistics (

The schedule for our next conference is here: Schedule for the Second Historical Analysis Annual Conference (HAAC), 17 – 19 October 2023 | Mystics & Statistics (