This is cut-and paste for the old discussion at e-budo or something, and of course it is only one study, but ... From Budo Perspectives, ed. Alexander Bennett; Chapter 7 - Budo as a Concept: An analysis of budo's characteristics. Irie Kohei. This work cites the following japanese publication (Suzuki Masaya, banana no kubitori: Sengoku kassen isetsu {Swords and head taking: Another view of Sengoku period battles}. Heibonsha, 2000.) "According to Suzuki Masaya, in battles from the mid-fourteenth to the mid-fifteenth centuries out of 554 examples, the percentage of casualties caused by arrows was 86%, sword cuts 8.3%, rocks 2.7%, spears and stab wounds 1.1%. From the mid-fifteenth to the mid-sixteenth centuries 1461 examples are analyzed with arrow wounds at 41.3%, guns 19.6%, spears and stab wounds 17.9%, rocks 10.3%, and 3% for swords." J