"I watched it when it was first broadcast

So did I.

"sitting with my grandfather who served in the ranks for the whole war. His perception - I have no idea if it was formed at the time or if he was influenced by later reading - was one of generals well behind the front, on both sides, playing a game of chess, each piece representing 10s of thousands of men.

Crock of shit - where did you dig that from "Blackadder Goes Forth"?? Won't even start to pick it to pieces.

"It was expressed with despair. His emotion whilst watching was an embarassment for a young person."

Really?? Why?? Because his views were completely at odds with those of the veterans who were interviewed? Because that would have been the case - But there again had you watched the documentary you would have known that - wouldn't you?