From my last season that finished 6 weeks ago, all lifetime PB's and still improving:
100m - 11.86
200m - 23.83
400m - 52.54
I'll be 50 in 3 years so not as fast as the young guys and started training after 40. My training for last season was for short speed targeting the 100 & 200. Only ran one 400 as my very last race of the season and somehow it seems to be my best distance in comparison to other competitors in my age group. However, my 800 is absolutely terrible which I trained for 2 years ago and could only run a 2'16.
So it seems that my sweet spot is the 200/400 as I get smashed in the 60/100 and destroyed in the 800. Would this simply be an anatomical/muscle fibre type/energy systems type thing which lets one be good at a certain distance rather than being able to do a wide variety of distances?