punter57,
Although we don't agree on keep betting or stopping for the day, I just loved your post and have to agree with you completely, how can a kilo make difference in a horses performance.
I watched a race recently (can't remember where but has stuck in my mind) the fav was fighting it out with a 20/1 pop head to head in the straight and the 20/1 saluted the judge, the race commentators reaction was that the fav was beaten because of the pull in the weights.
I have never heard so much crap in my life, the weight difference was 1.5 kg's.
The 20/1 pop was just better on the day.
Beaten lengths is another misconception, and I have to agree with you it all depends on how the horse was ridden out in the final stages.
Did you see the post of the person that broke into a racecourse with his tape measure to check the marks on the rail to see how far a length was so he could put it into his data base , I have never laughed so much in a long time.

Cheers, and good punting.