There were many notable swordsmen like Miyamoto Musashi and Sasaki Kojiro who were swordsmen but ordinary Samurai rarely used Katanas on the field (although i think katanas were used more from like 1300's) how much were katanas actually used in combat and not just as a last resort
See here on the data we have on wounds by weapons type. Suzuki Masaya, one of the men who compiled the data, argues that, at least in the Sengoku when horse archery declined, the main use of the katana ended up being what they used to cut off the heads of dead or wounded foes.