YayMii wrote:
If we're speaking strictly mathematically, the star ratings are categorized by 1 significant digit, displayed to the hundredths (or 3 sigdigs for the majority of maps), and calculated at a floating point value. If only one digit is given in the lobby title, it should be mathematically safe to assume that anything within the class boundaries would be acceptable (given that this is how the game categorizes them anyways).
That being said, the limits of an actual lobby have absolutely nothing to do with mathematics, simply due to the fact that some people are more lenient than others when it comes to what they are willing to play although a lot people disapprove of my map choices regardless of difficulty lolrip.
I think you're misunderstanding the point of significant figures.
Suppose you have a meter stick that's subdivided into centimeters. Further suppose that these centimeters are not subdivided into millimeters, but that markings have been made halfway between each consecutive pair of centimeter markings. If you use this meter stick and find that an object is between 33.5 and 34 cm long, you can round this result and say that the object is 34cm long. This measurement would have 2 significant figures. When performing calculations with this number, you would report the result of the calculations using a number of significant figures that's determined according to specific rules. These specific rules prevent rounding errors accumulated along the way from finding their way into the final answer.
I think it's safe to assume that the numbers used by the difficulty calculator have enough decimal places and enough significant figures that star ratings could be given to
more than 2 decimal places without suffering from rounding errors accumulated along the way and they can certainly be given accurately to 2 decimal places. Including 3.5 when saying "4" isn't a matter of caring about significant figures, as this would be implying a degree of uncertainty that does not actually exist in the numbers used. The type of uncertainty that does exist in star ratings comes rather from algorithm imperfections, which very much do not respect mathematical rules of rounding or significant figures. A specific 5.6 star map may very well be easier for the average player than a specific 4.9 star map, for example, and a player may consider both of these to be de facto 5 star maps.
Some people do use "4-5" to mean "3.5 - 5.5", but in most cases, I would expect this to stem either from not wanting to use decimals (which makes the notation ambiguous) or from following the conventions the game uses when sorting maps by star rating. Using this convention on the basis of significant figures is simply not correct.