Green Number and other IIDX Math

Exagon · 02-25-2009, 02:36 PM

Are you addicted to your comfortable SUDDEN+ Green Number on GOLD and or TROOPERS? Have you ever gone back to an earlier CS style and missed it? Ever wondered how stuff is calculated? Well, these handy formulas should help you out.

So, let's start with how the Green Number is calculated (abbr. GRN). Stolen from another thread about this a while ago, the formula is

where GRN = Green Number, BPM = BPM of the song, SPD = HS Setting*, SUD = SUD+ Number.

*Note: The HS Setting is the real meaning of whatever HS you have set, i.e.,
HS0 = 1.0x
HS0.5 = 1.5x
HS1.0 = 2.0x
HS1.5 = 2.25x
HS2.0 = 2.5x
HS2.5 = 2.75x
HS3.0 = 3.0x
HS3.5 = 3.25x
HS4.0 = 3.5x
HS4.5 = 3.75x
HS5.0 = 4.0x.
So, if for example you have HS set to HS4.0, SPD = 3.5.

Using this formula, we can solve for SUD, i.e. the SUD+ number to set on styles that don't show GRN:

Note that the value of SUD will be negative if the second term exceeds 1000. This just means that the HS Setting is too high for the BPM. Knowing this, we can find the threshold value of the Effective BPM, which is BPM times SPD:

This formula assumes that the player has HS5.0 set. It finds the BPM under which SUD+ will always be required to achieve GRN.

Another useful value is the Effective BPM (BPM times SPD) associated with the Green Number:

Now, for some sample calculations!
I read at GRN = 277. Say I want to play earth scape on IIDX RED, which doesn't show GRN. I want to know what to set my SUD+ to so it feels the same, i.e. GRN = 277.
As a general rule, I want to set my SUD+ according to the max BPM, which in the case of earth scape is BPM = 94. Clearly 94 is well below the BPMThreshold for GRN = 277, which is approximately 157 bpm. Applying the formula:

I hope these formulas help some of you to improve your scores.

m335h73r of PBJ · 02-25-2009, 02:51 PM

too much math.

Edit: What about pre RED styles, huh? What do I set my towel at to get a proper green number?

aeriyu · 02-25-2009, 03:14 PM

Well if you're not willing to do the math I guess you'll have to stick with whatever it is you're doing right now.

As for pre-RED, perhaps you could put sticky notes beside your TV... every 100 or so or something. Again, whatever works...

m335h73r of PBJ · 02-25-2009, 03:39 PM

troll failed :<

Exagon · 02-25-2009, 04:21 PM

Quote:

Originally Posted by The Windex Man

troll failed :<

I lol'd.

Just use the SUD equation you lazy assface.

jackwang1989 · 02-25-2009, 04:22 PM

For red, I wrote a table showing what height of towel I should use based on bpm ( from 100, 105 to 200 and 250). I got these values from gold and DJT.

m335h73r of PBJ · 02-25-2009, 04:25 PM

Quote:

Originally Posted by Exagon

I lol'd.

Just use the SUD equation you lazy assface.

why don't you come over here and make me

squeethehobo · 02-25-2009, 04:35 PM

To take this and apply it somewhat more reasonably, one can have a 'desired green number/high speed/sud+' table.

Suppose we go by what I like: Green 280 and SUD+ right around three hundred.

I can then make a table of 'BPMs/High Speeds' with my desired sud+/green number. This is actually simple enough to remember and use permanently.

105 - HS5
120 - HS4
140 - HS3
155 - HS2.5
170 - HS2
190 - HS1.5
210 - HS1
280 - HS0.5
320 - $%!&
400 - HS0

5% more bpm = 5% more lane needs to be visible. Generally speaking, often 1 notch of the sud+ = 1 green number.

AceJay · 02-25-2009, 04:36 PM

lollin here

Exagon · 02-25-2009, 04:36 PM

Quote:

Originally Posted by The Windex Man

why don't you come over here and make me

Why don't I :stewart:

TOFU!! · 03-02-2009, 10:12 AM

Wow, thank you so much for this! Happy Sky and Distorted will be much more enjoyable now!

Exagon · 03-02-2009, 11:35 AM

Quote:

Originally Posted by TOFU!!

Wow, thank you so much for this! Happy Sky and Distorted will be much more enjoyable now!

Nice, finally someone who found some use for it!

Blackraven · 03-02-2009, 09:27 PM

Hmm........

Quite a neat and interesting tidbit and piece of FYI.......though personally, I still never understood what the GREEN number is for (we don't have EMPRESS here yet atm so yeah).

Anyways, this is quite neat (and obviously even more mind-boggling than the formula to compute for EX score). So yeah, I have nothing more to add on.

PooIs · 03-03-2009, 12:57 AM

Quote:

Originally Posted by Blackraven

Hmm........

Quite a neat and interesting tidbit and piece of FYI.......though personally, I still never understood what the GREEN number is for (we don't have EMPRESS here yet atm so yeah).

Anyways, this is quite neat (and obviously even more mind-boggling than the formula to compute for EX score). So yeah, I have nothing more to add on.

The Green Sudden+ number is the number of milliseconds that the notes remain on the screen from the bottom of the Sudden+ cover to the red line at the bottom of the screen. This means that you can set a specific green number and use it for every song and have a consistent speed that you read notes at across the board.

Also, the EX score is not hard to figure out. Just/Perfect Greats=2 pts.;Greats=1 pt. Goods and below=0 pts. Total possible EX score for any song equals 2*total notes for the note chart. Letter grades: AAA=8/9, AA=7/9, A=6/9, etc. Not hard at all.

froz_loki · 03-03-2009, 11:37 AM

Quote:

Originally Posted by PooIs

The Green Sudden+ number is the number of milliseconds that the notes remain on the screen from the bottom of the Sudden+ cover to the red line at the bottom of the screen. This means that you can set a specific green number and use it for every song and have a consistent speed that you read notes at across the board.

Also, the EX score is not hard to figure out. Just/Perfect Greats=2 pts.;Greats=1 pt. Goods and below=0 pts. Total possible EX score for any song equals 2*total notes for the note chart. Letter grades: AAA=8/9, AA=7/9, A=6/9, etc. Not hard at all.

That was what I thought, but in turn after experiments we've figured out that the number should be multiplied by 2.

Guess what. I used my camera and made it capture 60fps. I made MAX LOVE (bpm 180, regul-speed in training mode) with original speed, green number at 1000. There were 4 spacings in the beat line. When I made it hi-0.5, space reduced by half. That proves the green number represents something like miliseconds.

After that, I did with hanaranman, original speed, green number 1000, and found out that the spacing went different (7 quaver spaces only), and confirmed that the number is not representing something like bar line portion. Finally, through calculation with BPM and timing, we see that with the number 1000, it means that the note needs 2000ms to drop from the cover to the judgement line.

Relevant videos could be supplied in request