This puzzle is part of the Monthly Topic Challenge #1: Restricted Title: xkcd 1xxx

Below, you will see a map with twenty UN members or observer states labelled with one or more letters from A-G (except one, which is labelled 'X'). Additionally, seven images of basketballs are presented, numbered 1-7.

TASK: Deduce the map labelling rule that enables you to pair up each letter A-G with exactly one number 1-7. Additionally, explain with justification which letter(s) should take the place of the black 'X' near the centre of the map.

(Click image to enlarge)

For avoidance of doubt, the labelled countries on this map are (in alphabetical order): Democratic Republic of the Congo, Estonia, eSwatini, Ethiopia, Guinea-Bissau, Liechtenstein, Netherlands, North Korea, North Macedonia, Palestine, Saint Kitts and Nevis, Saint Vincent and the Grenadines, São Tomé and Príncipe, South Korea, South Sudan, Switzerland, Turkmenistan, United Arab Emirates, United States, and Uzbekistan.

I think the X should be replaced by

D

First off

The seven images at the bottom are all a part of the logo of a different NBA basketball team. Namely (in order)

Brooklyn NetsIndiana PacersMiami HeatOklahoma City ThunderOrlando MagicPhoenix SunsWashington Wizards

The mapping rule:

Each state gets assigned those basketball teams which names (excluding the city) can be made using the letters of the state. E.g. for "Switzerland (EG)", we can make "wizards" and "nets", but not any of the others. In the end this gives us the following map:

A = Miami HeatB = Indiana PacersC = Oklahoma City ThunderD = Phoenix SunsE = Brooklyn NetsF = Orlando MagicG = Washington Wizards

So the X

must be "D", as only "Suns" can be made out of "South Sudan"

• Indeed, this is the correct solution :) You've made an unspoken deduction in your first step though, which might be useful for some users to have explicit in the answer, namely rot13(gur 'vzntrf bs onfxrgonyyf' ner cnegf bs gur ybtbf bs AON grnzf - fbzrguvat V qryvorengryl arire npghnyyl fcryyrq bhg va gur chmmyr frg-hc... Lbh'ir whfg whzcrq fgenvtug gb 'Gur frira onfxrgonyy grnzf ner...' juvpu zvtug yrnir n srj crbcyr guvaxvat 'Jurer qvq gung pbzr sebz??')
– Stiv
Commented Jul 3, 2022 at 22:23
• Thanks for adding that clarification, the checkmark is yours :) In fact, on consulting the two lists required when making this question, these are the only such examples when using simple country names. I got totally lucky that all of the required logos actually featured basketballs!
– Stiv
Commented Jul 4, 2022 at 8:18