I am left handed, I use my mouse buttons for strafing left and right and the number keypad on the right for my foward back. Subsequently its easy for me. number 8 foward, 5 backward and 1 for sprint, 7 to jump since the mouse 3 ( what I usualy jump with) is reserved for weapons configuration .) Number 4 is fire and 6 is alternate or zoom. I can play right handed as well and do so when using vehicles but when I am on foot, left handed rules (yes i have two mice one on each side of my keyboard)
That is about the most bastardized control scheme I think I have ever come across in my 16+ years of FPS gaming -- almost to the point that it elicits feelings of indignation and the need to break something.