Its all query tools. I try to aim for where the horses higher up on the handicap have an advantage, in that, weight is less of a benefit to the lower quality of horse.
Like yourself I am getting on a bit, and I’m not as fast as what I once was, so I’m using the same logic with the horses. The younger horses should have the speed advantage over the older ones, but not normally the same power. As Jan 1st changes all the horses ages there is a bias towards the younger ones. If you start using the filter you will see that there is a different between the first 3months and April May. I don’t know why, but I guess handicapper is catching up, weather changes, horses over raced, among some of the reasons.
Keep using the filters as it took me quite some time to whittle down positive strains, and even these can easily go south over the next 3 months as they are based on only 3-5 years of figures for early Spring.