Grass Training

Many athletes and other sportsmen like training on grass and there are lots of stories on the subject. For instance, there is the one about Peter Shilton, England's Number One Goalkeeper at the times telling Brian Clough on a European trip that there was no grass pitches to train on. Clugh said "I haave just the place for you to train on, young man. Come with me." And he led him to alarge road junction which had a big grass covered roundabout - and the English goalkeeper trained on the roundabout, ptactising shot stopping with jackets for goal posts. I remember Chris Robison - Scottish, English and Great Britain cross country internationalist and international 10000 metres runner - saying that if he could get a good grass track he would never train anywhere else.
At one time when I was asking around about training with an Achilles injury I was told by an Empire Games silver medallist from VPAAC to run on grass because it was kinder to the knees and ankles; a very famous marathon runner from Aberdeen said that you should train on good road surfaces because they would not twist and tug at the ankle when I was running. So I hedged my bets and trained on the Boule where the grass was good and soft and flat without being tussocky at all!
What's the thing about grass? Probably because there is a bit if give in it, probably because it is a more natural surface to run on and also, I suspect, that it is usually away from traffic with the associated noise and fumes.