Shikamaru in my opinion is one of the best fighters I have ever seen. He can be very deadly if he has the motivation and doesn't consider the fight to be a drag lol. The reason I think Shikamaru is one of the better fighters is because his mind is one of his greatest strengths. This kid can come up with hundreds of different strategies to take on his opponents with the the quickness! He examines his opponent inside and out, from fighting styles, attacks, movements, etc. With this knowledge he comes up with ways to counter every move they make. So when Shikamaru is serious in battle, then his enemies have one hell of a fight on their hands!