Great chart and comparison, few things eg seems variability of...

Great chart and comparison, few things eg seems variability of Decennial is larger than Presidential in the pictorial representation; for emphasis or due to cycles used in 10yr v 4yr being 2.5times less and so naturally a greater statistical variation? Am thinking the Decennial might be governed by the late 1920s to early 30s and possibly its +10yr into WW2 cycle repeat, yes that's a cycle repeat and valid, but starting at say 1950 with SPX, would think a change of sorts.

Has got me started on a cycle program, hopefully a week or two to get some quick cycle averaged results of any duration including stats up and running.