This is in the spirit of the What is a Word/Phrase™ series started by JLee with a special brand of Phrase™ and Word™ puzzles.
If a word conforms to a special rule, I call it a Plot Word™.
Use the following examples to find the rule.
In case you want it as a CSV:
Plot Words™, Not Plot Words™
fox, wolf
may, june
wall, walk
pork, ham
beef, cow
cage, coop
spoon, fork
cull, call
gun, knife
face, mind
hedge, shrub
room, house
The puzzle relies on the series' inbuilt assumption, that each word can be tested for whether it is a Plot Word™ or not on its own.
These are not the only examples of Plot Words™, many more exist.
Hint 1
The original name for this puzzle was What is a Graph Word™?
Hint 2
y=mx+b
Hint 3
1 is 01, 2 is 02, 3 is 03 and so on.