> [!quote] [Fireside Friday, April 22, 2022](https://acoup.blog/2022/04/22/fireside-friday-april-22-2022/) by [[Bret Devereaux]] > **The thing is, the tooth to tail ratio has tended to shift towards a longer tail over time, particular as warfare has become increasingly industrialized and technical.** > > The Roman legion, for instance, was essentially all tooth. While there was a designation for support troops, the _immunes_, so named because they were immune from having to do certain duties in camp, these fellows were still in the battle line when the legion fought. The _immunes_ included engineers, catapult-operators, musicians, craftsmen, and other specialists. Of course legions were also followed around by civilian non-combatants – camp-followers, sutlers, etc. – but in the actual ranks, the ‘tail’ was minimal. > > You can see much the same in the organization of medieval ‘lances,’ – units formed around a single knight. The Burgundian ‘lance’ of the late 1400s was composed of nine men, eight of which were combatants (the knight, a second horsemen, the _coustillier_, and then six support soldiers, three mounted and three on foot) and one, the page, was fully a non-combatant. A tooth-to-tail ratio of 8:1. That sort of ‘tooth-heavy’ setup is common in pre-industrial armies. > > modern warfare – that is warfare since around 1900 – is dominated by artillery and [other forms of fires](https://acoup.blog/2022/03/25/miscellanea-a-very-short-glossary-of-military-terminology/). Artillery, not tanks or machine guns, after all was the leading cause of combat death in both World Wars. Suddenly, instead of having each soldier carry perhaps 30-40kg of equipment and eat perhaps 1.5kg of food per day, the logistics concern is moving a [9-ton heavy field gun](https://en.wikipedia.org/wiki/BL_8-inch_howitzer_Mk_VI_%E2%80%93_VIII) that might throw something like 14,000kg of shell per day during a barrage[1](https://acoup.blog/2022/04/22/fireside-friday-april-22-2022/#easy-footnote-bottom-1-12724 "At the Somme in 1916, the British artillery fired around 1,050 shells per artillery piece in just about a week; around 150 a day."), for multiple days on end. Suddenly, you need a lot more personnel moving shells than you need firing artillery. > > As armies motorized after WWI and especially after WWII, this got even worse, as a unit of motorized or mechanized infantry needed a small army of mechanics and logistics personnel handling spare parts in order to _stay_ motorized. [Consequently, tooth-to-tail ratios plummeted, inverted and then kept going](https://en.wikipedia.org/wiki/Tooth-to-tail_ratio). In the US Army in WWI, the ratio was 1:2.6 (note that we’ve flipped the pre-industrial ratio, that’s 2.6 non-combat troops for every front line combat solider), by WWII it was 1:4.3 and by 2005 it was 1:8.1. Now I should note there’s also a lot of variance here too, particularly during the Cold War, but the general trend has been for this figure to continue increasing as more complex, expensive and high-tech weaponry is added to warfare, because all of that new kit demands technicians and mechanics to maintain and supply it. He's explicitly writing this as a primer for how to write scifi space battles more accurately.