The tenth of Trevor Dupuy’s Timeless Verities of Combat is:
Surprise substantially enhances combat power.
From Understanding War (1987):
Achieving surprise in combat has always been important. It is perhaps more important today than ever. Quantitative analysis of historical combat shows that surprise has increased the combat power of military forces in those engagements in which it was achieved. Surprise has proven to be the greatest of all combat multipliers. It may be the most important of the Principles of War; it is at least as important as Mass and Maneuver.
I have already written quite a bit on Dupuy’s conceptualization of surprise so I won’t go into it in detail here. These previous posts provide a summary:
Dupuy’s analysis focused on how surprise influenced combat power by enhancing the mobility and reducing the vulnerability of the side with surprise, and by increasing the vulnerability of the side that was surprised. In 2004, TDI undertook a study for the late Andy Marshall’s Office of the Secretary of Defense/Net Assessment to measure the historical combat value of situational awareness (more knowledge by one side than the other) and informational advantage (better knowledge by one side than the other) and how each of these factors related to surprise in combat. Chris Lawrence detailed this research and its conclusions in chapters 10 and 11 in his 2017 book, War by Numbers: Understanding Conventional Combat.
In general, the study found that both superior situational awareness and better information enhanced combat power, though perhaps not quite as much as inferred from the relevant literature. It also confirmed that surprise conferred an even greater combat power benefit, above and beyond that provided by battlefield awareness or informational advantages. It also suggested that the primary benefit of a situational or knowledge advantage in combat was not in achieving surprise over an enemy, but in preventing an opponent from achieving surprise itself.
These results, though quite suggestive, were tentative and more research is necessary. However, no follow on studies on this subject have been funded to date.
Jim Storr, in his Human Face of War (2009), put it that achieving surprise was the single most valuable thing a tactical commander could do, normally “having an effect greater than a 10:1 force ratio”. Or to put it another way, if surprise is achieved, success is largely independent from force ratio; if it is not achieved, it is highly dependent on force ratio. This seems to be derived from the following paper, although I don’t think I have seen a copy: The Effects of Shock and Surprise on the Land Battle, Defence Operational Analysis Establishment Memorandum R9301, August 1993.