Simfiles Difficulty

Hello ! I 've realized that there is no " standard" for the difficulty of simfiles (which is annoying when you want to train ) .
So I created a system that allow everybody to standardize simfiles easily :

x / y = z

x = Total arrow simfiles
y = song length in seconds
z = Result

After, we have simply to match the value obtained with this table below and we have our standardize simfiles.


For example,
if z = 2.02, so the simfile difficulty is 6
if z = 1.45, so the simfile difficulty is 4

What do you think about my technic? Do you think that we can make something (like a freeware or a website for example) to normalized simfiles pack with this method?
Sorry for my bad English, I’m French.

The problem with this method is that it doesn't take into account the complexity of a song, only the density of the notes. For example, a song could have hundreds of arrows but have absolutely no footswitch, crossovers or even jumps, whereas a song with the same amount of notes WITH those types of patterns would warrant a higher difficulty.

Hm ... You're right .

In this case, it's possible to adapt. For example :

- Normal arrow 1 : 1
- Footswitch 1 : 2
- 1 crossovers : 1.5
- 1 jumps : 0.5
- 1 mines : 1

( This is an example with false values)

What do you think ?

I was also planning on coming up with a formula myself, but more complicated. To get an accurate difficulty rating system, you need to take into account:

- Note density (Note count - 1 / seconds from first to last note)
- Jumps, hands, and quads (so for notecount, make jumps count as 2 notes, etc)
- Rhythm placement (color of notes - this is one aspect of Chaos)
- Maximum Note Density (aka Voltage)
- BPM changes (total BPM change value)
- Pattern complexity (You would need a way to factor in double-steps and crossovers and spins)

There might be other stuff as well, but I think that covers most of it.

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Average NPS means nothing. There are difficult charts like "To Luv me I *** for You" (Chino, ITG 16) that are very low in average NPS but are very difficult (NPS ramps up at the very end)

This formula would rate charts like that as easier than, say, a stream-dense ITG 13.

StomperZ is a very good objective rating system, it's just not public yet.

Darkanine > it's interesting ! If you are interested, we can work together on a system like that! (I'm web-developer, maybe we can create an online converter, why not?)

tj28 >What's StomperZ ?

One already exists it don't know the site but yeah one exists and it's accurate or Stream charts

Wow ! It's a good news ! If someone know about this site it will be my hero !

Density, technicality and many other factors go into ratings. You cannot get by with such a trivial formula.

That said, I know a guy who I think is working on a program that can be trained to predict the difficulty of charts but its really not an easy thing to do.

Also 7 arrows per second is piss-easy relative to your scale. Dragonforce 14s have higher densities than that even with tons of easy stuff, if you condensed many stream 15s you'd end up with densities nearly twice as high. I know that we're talking about X-scale here, but it is the same exact story except then your densities are higher AND the patterning gets really weird at 18s and up, especially in new mixes where 18+ means hard patterning filled with a bunch of other gimmicks.

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I don't know if there's really a way to operationally rate simfiles from a formula. You'd probably be better off rating them individually on a case-by-case basis.

If you want to do a tool like this you need to know a bit about chart structures. If you don't understand any of these terms: doublestep, drill, crossover, turn, step-jump, jack-hammer then you won't be able to do good program to measure difficulty.

If you understand those things then you can start the analyze by using official charts (both DDR and ITG). Take into account following:
- average arrow density in bars (as some songs tend to have easy beginnings and then pick up pace at end)
- do song have speedups, stops or any other tricks (negative BPM, attacks)
- check how many unique patterns song has, does it have doublesteps or not, is everything doable at given speed / arrow density
- analyze chart flow (is the song a stream of 1/4th or maybe it has 1/32nd gallops).

I found the site if you want it
http://smleaderboards.net/difficulty_calculator

WOOOOOOW !!!!! Thank you very much Junko ! You are my HERO !!! <3

The only problem with the site that Junko just linked to is that it's made specifically with keyboard files in mind. You won't get accurate pad chart ratings there.

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I stated that it is used for stream charts, and I don't even use it I just said it was there.

stream charts doesn't necessarily equal keyboard charts thou

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There are some vague guidelines for the ITG scale... here's how I rate mine at mid-to-high BPMs
1. almost all half notes, or just waaay too easy
2. the "upscale beginner chart"
3. more quarter notes than a 2, but not to the extent of a 4
4. based entirely in quarter notes
5. some 8th notes, comparatively easier than a 6
6. centered around 8th rhythms, not often Expert-worthy
7. the average licensed Expert chart
8. more complex rhythms, often has 16ths
9. tougher, generally a 13 or 14 on X-Scale
10. the "easy boss song"
11. an EXTREME era boss song
12. a SuperNOVA era boss song
13. Replicant D-ignition

Bump because question- I have a file that contains 16th gallops at 100bpm, and it's currently rated 5. Should I raise it to 6? There is also a 4-measure-long 8th stream towards the end.

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I would say a 6 depending on the gallops. 16th gallops are technically harder than 8th streams. If there are a lot of gallops (15+) I'd go with a 6. If it is mostly short 8th patterns with only a few gallops, go with a 5. Also, if you show me the chart through the ZIv chart viewer or through http://telperion.ws/smexy/smexy-v2.htm I can judge it better.

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