We have 66 engagements in our database from after World War II. There are 51 cases from the Arab-Israeli Wars and 15 cases from the 1991 Gulf War.
Arab-Israeli Wars 1956-1973 (51 cases)
Force Ratio…………………Percent Attacker Wins………………..Number of Cases
0.54 to 0.97-to-1……………….76%…………………………………………….17
1.00 to 1.47-to-1……………….82……………………………………………….11
1.51 to 1.99-to-1……………….50…………………………………………………4
2.04 to 2.25-to-1……………….50…………………………………………………4
2.90-to-1……………………….100…………………………………………………1
3.03 to 3.59-to-1…………………0…………………………………………………2
3.50 to 3.96-to-1……………….25…………………………………………………4
4.11 to 5.87-to-1……………….40…………………………………………………5
6.06-to-1……………………….100…………………………………………………1
8.02 to 12.18-to-1…………….100…………………………………………………2
Now, this data is highly variable, with the largest number of attacks being conducted at less than one-to-one odds and the attacker winning 76% of the time. This is because of a significant difference in the combat capability of Israeli forces compared to the Egyptians, Syrians and other Arab armies that they are engaged with. This difference is well documented and discussed in more depth in my book War by Numbers. Of the 17 attacks at less than one-to-one odds, 16 were conducted by the Israelis and only one attack was conducted by the Arab armies. The Iraqi attack at those low odds was resoundingly defeated (Tel el Hara, 11 October 1973).
There is a similar performance disparity between the German and the Soviet armies in 1943. This also affects the force ratio data from World War II. We will separate these cases out by who the attacker is just to clarify the results. In the case of the Gulf War, the difference in morale, motivation and performance of the two armies were extremely disparate. This is a fairly extreme case, although not the only such case in history.
Gulf War (1991):
Force Ratio…………………..Percent Attacker Wins…………………Number of Cases
0.20 to 0.21…………………………0…………………………………………………..2
0.64 to 0.93………………………..67…………………………………………………..3
1.10 to 1.16………………………100…………………………………………………..2
None between 1.16 and 2.47
2.47……………………………….100………………………………………………….1
2.60 to 2.86………………………100………………………………………………….5
3.00 to 3.26………………………..50………………………………………………….2
One is hesitant to draw any conclusions from this data. The one attack that failed at three-to-one was the Iraqi Army attack at Khafji 29 January – 1 February 1991. In fact, all four failed attacks in the data set occurred when the Iraqis were attacking.
Anyhow, these databases can certainly be expanded and further analysis can be done, but good luck finding the three-to-one rule in this data that results in the defender winning 50% of the time. It is clear that from 1600 to 1991 that the attacker won more often than not at two-to-one odds or even lower, depending on the period and the forces involved. There is really no historical evidence supporting the Army version of this rule that I know of. I have been in this industry for over three decades and have not seen such evidence. I am not aware of any databases the size, depth or range of ones used here. If this historical data does not establish the rule, then where is the historical data that does?
