How To Use The Stamp Condition System I Invented

While there is little to no chance that the industry will adopt a new system, you are welcome to categorize and grade your own stamps in any way that you like for your own inventory.

The problem with a singular numeric score as others have pointed out is that it aggregates and dilutes all the condition factors into a single linear grade, mostly focused on centering.

If you want to use a 5 point score, how about making it a three-part score with 555 being a top score. For mint stamps, the first digit is centering, the second digit is gum, and the 3rd digit is everything else.

For gum, you could use something like:
5=NH
4=NH but gum skips or other minor blemishes
3=LH
2=hinged or disturbed gum
1=HR
0=NG

The 3rd digit represents any faults or other condition anomalies.
5=sound
4=nibbled perf, tiny corner crease, perf crease, etc.
3=pulled perf, minor thin, crease
2=small tear, multiple pulled perfs, heavy crease
1=torn in half and repaired
0=parts of stamp are missing
Multiple problems drop it down a notch (pulled perf and thin knock it down from a 3 to a 2).

To summarize, a well centered, LH, stamp with a tiny corner crease would get a score of 534.

For used stamps, the middle digit would represent the quality of the cancellation rather than the quality of the gum.
5=light, clear, face-free cancellation
4=fairly light but smudgy cancel
etc.

I have not (and will not) use such a system myself, but if you are so inclined to inventory your own collection in such a way, it is some food for thought.

Thanks for the advices ! That helps !

Thank you, ZebraMan for this breakdown on damage:

The 3rd digit represents any faults or other condition anomalies.
5=sound
4=nibbled perf, tiny corner crease, perf crease, etc.
3=pulled perf, minor thin, crease
2=small tear, multiple pulled perfs, heavy crease
1=torn in half and repaired
0=parts of stamp are missing
Multiple problems drop it down a notch (pulled perf and thin knock it down from a 3 to a 2).

I have long been using basically this system to decide whether to keep a stamp, to put it in my big "damaged stamps" box, or to throw it away.

For modern, low value stamps (below $5CV), I will keep only a 5 or a 4 and will replace the 4 whenever I get a chance.

For older or HV stamps, I might keep a 3 or even in very rare cases a 2, but will make an annotation in my album as to the extent of the damage.

It's useful to have this scale spelled out.