The Eddington number is well known to astronomers as an estimate of the total number of protons in the known universe (NEdd, see links [1] and [2] below).
Less well known is that Eddington had a second number named after him.
I am going to call his first number ED1 and the second number ED2.
Eddington was an enthusiastic cyclist and wanted a way of keeping a score of his most frequent best distance cycle rides.
ED2 - his second number - is the number of days that you have cycled that same number of miles.
To quote the wiki page [1]:
"The Eddington number in the context of cycling is defined as the maximum number E such that the cyclist has cycled E miles in E days."
Eddington's own life time achievement for cycling was an ED2 of 84
i.e. he managed eighty four days when he had cycled 84 miles.
So ED2 is not your personal best ever score; it's the best number you have managed of that distance but only if repeated that number of times.
ED2 says something about consistency .... so its quite a challenge to better it !
You can have an ED2 number for anything that challenges you.
So for example although I am not a great cyclist I do enjoy juggling, walking / hiking and longboarding etc.
My personal ED2 numbers might be:
5 ball juggling = 50 (i.e. 50 days when I managed 50 throws of 5 balls)
Hiking = 20 miles
Longboarding = 15 miles
Cycling = (probably about) 20 miles
Note: ED2 is dependent on the units you use.
For example 10 miles is about 16 km but an ED2 of 10 (miles) is 10 times you cycled 10 miles which is easier than an ED2 of 16 (km) which would be 16 times for the same distance!