Tablebase descriptors

[Robert Pope]

Is there a clear definition for describing potential tablebase files? Ones like KRK instead of KKR are pretty straightforward, but what about more complicated ones, like is it KQBNKRRNP or KRRNPKQBN? Is there an unambiguous correct way to list them, in general?

[phhnguyen]

Typically sort order:
- the side has more pieces come first
- if two sides have same piece number, who has more material come first
- for each side, bigger piece comes first

For your example I think KRRNPKQBN is typically accepted.

[Sven]

Typically sort order:
- the side has more pieces come first
- if two sides have same piece number, who has more material come first
- for each side, bigger piece comes first

For your example I think KRRNPKQBN is typically accepted.

But what exactly is "more material"? 9-5-3-3-1 based? E.g. KRRNKQBP would still be equal. The second sorting rule should be more like this:
"if two sides have the same number of pieces then the side with the biggest piece comes first"

[Sesse]

Lexicographic on strongest piece. So QPPP (or QNNN) is stronger than than RRRR.