When u get a 2 yr old with the potential bar 8/10 full, would that change as he ages or should I move on my 2 year olds who dont have much potential?? Having a few that have very poor constitution and not much Potential despite breeding 2 monsters together, it's so frustrating

Some change some don't. Have yet to have a full bar for two year olds except for sprinters. Have many at age 4 or 5. My stayers bars are not great at 2 ( 7 or 8 out of 10 ). Sometimes a horse with say 50% dark green and 30% light green of 80% bar becomes 80% dark green and 20% light green of a full bar before become a full dark green bar

If the bars are 50% they stay useless though.

I normally look at other stuff like speed rating as well.

Some observations.

The realised/absolute potential bar never goes up between 2 and 3 as far as I have seen. I have seen the realised potential decrease though whilst the absolute potential stays the same.

Between 3 and 5 years of age the realised and absolute potential bars increase moreso from 3 to 4 and less from 4 to 5. After the realised potential decreases.

Some horses never realise their absolute potential. The majority of horses I see at 2 which don't realise their absolute potential never do so even by 5. I've seen the odd horse that will achieve this by 5 years of age.

Personally I discard a lot of horses where the realised potential is much less than the absolute potential.