My Fav Technique

Hello friends, after exploring the techniques of pencil drawing like vector, contour, hatching, shading, gesture, scribbling am still not satisfied and keep exploring other techniques. Meanwhile I came across a drawing by Ernst Cole in a academic class, which attracted me very much. It was not gesture nor crosshatch or shading, it was combination of all three to me... so tried my hands on the one which atracted me. Althouh I could not match the original sketch I almost achieved it 90%.

If you notice closely, its pretty much simple with very few lines, but the depth of matter revealed in those lines are tremendous. The expreesion in the eyes, its sharpness and thinking pose... everything has been portraited very well. Rather drawing the complete picture, he most important dark shades are shown exactly and the rest are made with shades and crosshatching. The portrait loks like our great poet Rabindranath Tagore, but I dont know whether it was him because I have not seen this drawing in any site apart from this one academic book. I am planning to draw more with just lines and either shading or crosshatching to reveal the depth of expression.

This may be one form of vector sketches too, but the shading or hatching makes it stand apart from vector.
I used only HB and 2H pencils for this drawing. Asusual want all your valuable comments in improving myself.