## Contents

Introduced in DDRMAX -DanceDanceRevolution 6thMIX-, the GROOVE RADAR (グルーヴレーダー) is a graphical representation of a song difficulty using a pentagon shape. Originally meant to be the successor to the traditional Feet/Number Level system, both the Feet/Number Level and GROOVE RADAR have been used since DDRMAX2 -DanceDanceRevolution 7thMIX- due to negative reception over the GROOVE RADAR being the only representation of song difficulty. Starting from DanceDanceRevolution (2014), the GROOVE RADAR values for a chart are always shown on the song select screen. Different values will appear on the GROOVE RADAR depending on the difficulty currently selected for a song. Before DanceDanceRevolution SuperNOVA, BEGINNER charts had no Groove Radar data at all.

Note: The GROOVE RADAR calculations are derived from DanceDanceRevolution (2013) but are valid for later installments of the DanceDanceRevolution arcade series.

## STREAM

STREAM is denoted as the amount of sets of steps that are right after one another (step density) in the song. The song with the highest STREAM values is EGOISM 440, which has Single and Double CHALLENGE charts with STREAM values of 226 and 270, respectively.

It is actually calculated as the average number of steps per minute, calculated as the following:

`Average Step Density = 60 × (Steps + Shock Arrows) ÷ Song Length (sec)`

The Average Step Density is the average step density (steps per minute), always rounded down to the nearest whole number.

• If Average Step Density is equal to or less than 300, STREAM value = Average Step Density ÷ 3.
• If Average Step Density is equal to or greater than 300,
• and the play style is Single, STREAM value = (Average Step Density - 139) × 100 ÷ 161;
• or the play style is Double, STREAM value = (Average Step Density - 183) × 100 ÷ 117.
Examples
1. Synergy For Angels (Single EXPERT): 535 notes in 114 seconds, Average Step Density = 281, STREAM = 93.
2. EGOISM 440 (Single CHALLENGE): 811 notes in 96.545 seconds, Average Step Density = 504, STREAM = 226.
3. Triple Journey -TAG EDITION- (Double CHALLENGE): 712 notes in 102.5 seconds, Average Step Density = 416, STREAM = 199.
Rankings (Single)
1. EGOISM 440 (CHALLENGE): 226
2. MAX 360 (CHALLENGE): 222
3. 888 (CHALLENGE): 200
4. ENDYMION (CHALLENGE): 198
5. MAX 360 (EXPERT): 188
Rankings (Double)
1. EGOISM 440 (CHALLENGE): 270
2. MAX 360 (CHALLENGE): 247
3. ENDYMION (CHALLENGE): 224
4. POSSESSION (20th Anniversary Mix) (CHALLENGE): 223
5. Lachryma《Re:Queen’M》 (EXPERT): 204
Scoring

The player's STREAM rating on their MY GROOVE RADAR is added by way of taking the player's score on the chart, dividing it by 1,000,000, then multiplying it by that chart's STREAM value, and dividing it by 10. For example, if the player got a score of 699,300 on MAX 300's Single EXPERT chart (which has a STREAM value of 143), their STREAM rating on their MY GROOVE RADAR would reach 100.

## VOLTAGE

VOLTAGE refers to the peak density of the steps of the song. It is the highest density of arrows that appear on the screen at once in one measure (four beats). The chart with the highest VOLTAGE value is ACE FOR ACES' Single CHALLENGE, with 260.

To calculate VOLTAGE, find the average BPM of the song first. The average BPM is calculated as:

`Average BPM = 60 × Song Length (beats) ÷ Song Length (sec)`

where Song Length is determined both in beats and in seconds; both are measured from the beginning all the way to the end (when it says "CLEARED"). Once the average BPM is found, find the peak density (the maximum number of notes that occur in four consecutive beats) and divide by 4 to find the Average Peak Density Per Minute value, which is always an integer number. If a song has no stops or BPM changes, use the song's BPM instead.

• If Average Peak Density Per Minute is equal to or less than 600, VOLTAGE = Average Peak Density Per Minute ÷ 6.
• If Average Peak Density Per Minute is equal to or greater than 600, VOLTAGE = (Average Peak Density Per Minute + 594) × 100 ÷ 1194.
Examples
1. New Generation (Single EXPERT): 300 beats in 94.7368 seconds, Peak Density = 12, APD = 570, VOLTAGE = 95.
2. Blew My Mind (Single/Double CHALLENGE): 520 beats in 99.9474 seconds, Peak Density = 23, APD = 1794, VOLTAGE = 200.
Rankings (Single)
1. ACE FOR ACES (CHALLENGE): 260
2. Blew My Mind (CHALLENGE): 200
3. Cosy Catastrophe (CHALLENGE): 188
4. London EVOLVED ver.A (EXPERT/CHALLENGE): 177
5. POSSESSION (EXPERT/CHALLENGE): 161
Rankings (Double)
1. ACE FOR ACES (CHALLENGE): 247
2. Blew My Mind (CHALLENGE): 200
3. Cosy Catastrophe (CHALLENGE): 188
4. London EVOLVED ver.A (CHALLENGE): 177
5. POSSESSION (EXPERT/CHALLENGE): 161
Scoring

The player's VOLTAGE rating on their MY GROOVE RADAR is increased based on the maximum combo they have received on the chart. A full combo means that the player will receive the maximum VOLTAGE rating from that chart. For example, Blew My Mind's Single CHALLENGE chart has a VOLTAGE value of 200. If the player wanted to raise their MY GROOVE RADAR's VOLTAGE rating to 160, they would need to achieve a MAX COMBO of at least 534, as said chart has 665 notes and 2 Shock Arrows.

## AIR

AIR refers to the total number of jumps and Shock Arrows in the chart. POSSESSION (20th Anniversary Mix)'s DOUBLE CHALLENGE chart holds the current highest AIR value of 224.

It is calculated similarly to STREAM except only jumps and Shock Arrows are involved:

`Average Air Density = 60 × (Jumps + Shock Arrows) ÷ Song Length (sec)`

As with STREAM, Average Air Density is an integer number.

• If Average Air Density is equal to or less than 55, AIR = Average Air Density × 20 ÷ 11.
• If Average Air Density is equal to or greater than 55,
• and the play style is Single, AIR = (Average Air Density + 36) × 100 ÷ 91;
• or the play style is Double, AIR = (Average Air Density + 35) × 10 ÷ 9.
Examples
1. PARANOiA Revolution (Single CHALLENGE): 90 jumps in 110.167 seconds, Average Air Density = 49, AIR = 89.
2. Right on time (Ryu☆Remix) (Single CHALLENGE): 181 jumps + 63 Shock Arrows in 99.866 seconds, Average Air Density = 146, AIR = 200.
3. BRILLIANT 2U (Double DIFFICULT): 72 jumps in 75.2 seconds, Average Air Density = 57, AIR = 102.
Rankings (Single)
1. Right on time (Ryu☆Remix) (CHALLENGE): 200
2. TWINKLE♡HEART (CHALLENGE): 165
3. DYNAMITE RAVE("AIR" Special) (CHALLENGE): 159
4. POSSESSION (20th Anniversary Mix) (CHALLENGE): 152
5. Summer fantasy (Darwin remix) (CHALLENGE): 142
Rankings (Double)
1. POSSESSION (20th Anniversary Mix): 224
2. Right on time (Ryu☆Remix) (CHALLENGE): 200
3. ようこそジャパリパークへ (CHALLENGE): 195
4. TWINKLE♡HEART (CHALLENGE): 162
5. DYNAMITE RAVE("AIR" Special): 160
Scoring

The player's AIR rating on their MY GROOVE RADAR is increased based on how many jumps in the chart they hit with at least a Great and how many Shock Arrows they successfully avoid. New Decade's Single CHALLENGE chart has an AIR value of 112 and 100 jumps; if the player wanted to raise their AIR value to 100 by playing that chart, they would have to successfully hit at least 90 jumps in the chart.

## FREEZE

FREEZE is denoted as the total length of the chart's Freeze Arrows. D2R("FREEZE" Special)'s charts currently have the highest FREEZE value of 200.

It is calculated as:

`FA Rate = 10,000 × FA Total Length (beats) ÷ Song Length (beats)`

FA Rate is the average rate of Freeze Arrows. If two Freeze Arrows appearing at once start at the same time, only the longer end is counted.

• If FA Rate is equal to or less than 3,500, FREEZE value = FA Rate ÷ 35.
• If FA Rate is equal to or greater than 3,500,
• and the play style is Single, FREEZE value = (FA Rate + 2484) × 100 ÷ 5,984;
• or the play style is Double, FREEZE value = (FA Rate + 2246) × 100 ÷ 5,746.
Examples
1. Chinese Snowy Dance (Single BASIC): 85.0 total FA length in 300 beats, FA Rate = 2833, FREEZE = 80.
2. D2R("FREEZE" Special) (Single CHALLENGE): 239.0 total FA length in 252 beats, FA Rate = 9,484, FREEZE = 200.
3. DoLL (Double DIFFICULT): 137.75 total FA length in 316 beats, FA Rate = 4,359, FREEZE = 114.
Rankings (Single)
1. D2R("FREEZE" Special) (CHALLENGE): 200
2. CURUS (DIFFICULT): 173
3. in love wit you (EXPERT): 168
4. Freeze (DIFFICULT): 146
5. Freeze (BASIC): 144
Rankings (Double)
1. D2R("FREEZE" Special) (CHALLENGE): 200
2. in love wit you (EXPERT): 183
3. in love wit you (DIFFICULT): 156
4. Freeze (DIFFICULT): 144
5. Freeze (BASIC): 128
Scoring

The player's FREEZE rating on their MY GROOVE RADAR is increased based on how many Freeze Arrows they successfully clear with an O.K. judgement in the chart. D2R ("FREEZE" Special)'s Single CHALLENGE chart has 67 Freeze Arrows, and if a player wanted to raise their FREEZE rating to 150, they would need to successfully clear 51 Freeze Arrows in that chart.

## CHAOS

CHAOS refers to the amount of steps that do not match well with the beat of the song. The song CHAOS is notable for having very high CHAOS values for its charts, with its CHALLENGE charts having the current highest value of 200.

In practice, it is determined by multiple factors.

The first factor determining CHAOS is the number of non-4th (red) notes, determining the chart's Total Chaos Base Value. Each note has a Chaos Base Value assigned to it, calculated as the following:

`(Note Quantization ÷ Interval from Last Note) × Note Color Value × Number of Arrows`
• Note Quantization: 4th, 8th, 12th, 16th, 24th, 32nd, 48th, or 64th.
• Interval from Last Note: How far this note is from the previous one, based on its Note Quantization.
• Note Color Value: The color of the note as viewed with the NOTE ARROW COLOR option. Red (4th) notes have a value of 0, blue (8th) notes have a value of 0.5, yellow (16th) notes are always 1, and green (12th, 24th, 32nd, etc.) notes are 1.25.
• Number of Arrows: A single note yields 1, a jump yields 2, and a Shock Arrow yields 4 or 8.
• Note: The first note's Chaos Base Value is always 0.
Example: Valkyrie dimension (Single CHALLENGE), with 4,456.16.

The second factor determining CHAOS is Total BPM Delta, the sum of the BPM changes in the chart. As an example, Valkyrie dimension: 90 → (gradual speedup) → 240 → 480 → (stop) → 744 → (stop) → 186 → 93 → 186 → (24 stops) → 186 → 93 → 744 → 186 → (stop) → 186 → 46.5 → 390. The Total BPM Delta value is calculated as the change from one BPM to another (186 → 93 = 93). In the case of gradual BPM changes, simply take the highest BPM value, subtract it from the lowest, and get its absolute (non-negative) value. In the case of stops, use the BPM that is immediately used after the stop. If the song has no BPM changes or stops, the Total BPM Delta is 0. Valkyrie dimension's Total BPM Delta is 7,941.

The third factor determining CHAOS is song length, in seconds. Valkyrie dimension has a song length of 114.246 seconds. This affects the Average BPM Delta (per minute), which is calculated as:

`60 × Total BPM Delta ÷ Song Length (sec)`

Valkyrie dimension has an Average BPM Delta of 4,170.468624.

The fourth factor determining CHAOS is the Irregularity Degree, calculated as:

`Total Chaos Base Value × (1 + (Average BPM Delta ÷ 1,500))`

Valkyrie dimension's Single CHALLENGE chart has an Irregularity Degree of 16,846.

The fifth and final factor determining CHAOS is the Unit Irregularity Degree, calculated in integer form as:

`Unit Irregularity Degree × 100 ÷ Song Length (sec)`
• If the Unit Irregularity Degree is equal to or less than 2,000, CHAOS = Unit Irregularity Degree ÷ 20.
• If the Unit Irregularity Degree is equal to or greater than 2,000,
• and the play style is Single, CHAOS = (Unit Irregularity Degree + 21,605) × 100 ÷ 23,605;
• or the play style is Double, CHAOS = (Unit Irregularity Degree + 16,628) × 100 ÷ 18,628.
Examples
1. Fascination MAXX (Single BASIC): Total Chaos Base Value = 547.99359 and Total BPM Delta = 3,500 in 101.225 seconds, Unit Irregularity Degree = 1,290, CHAOS = 64.
2. Valkyrie dimension (Single CHALLENGE): CHAOS = 153.
3. CHAOS (Double CHALLENGE): Total Chaos Base Value = 4,116 and Total BPM Delta = 7,480 in 87.882 seconds, Unit Irregularity Degree = 20,628, CHAOS = 200.
Rankings (Single)
1. CHAOS (CHALLENGE): 200
2. ACE FOR ACES (CHALLENGE): 175
3. ORCA (EXPERT): 172
4. CHAOS Terror-Tech Mix (CHALLENGE): 169
5. CHAOS (EXPERT): 164
Rankings (Double)
1. CHAOS (CHALLENGE): 200
2. ACE FOR ACES (CHALLENGE)/ORCA (EXPERT): 188
3. CHAOS Terror-Tech Mix (CHALLENGE): 181
4. CHAOS (EXPERT): 177
5. Over The “Period” (CHALLENGE): 161
Scoring

The player's CHAOS rating on their MY GROOVE RADAR is increased when they clear a chart with as few Misses as possible. CHAOS' Double CHALLENGE chart has a CHAOS value of 200, meaning that if the player wanted to raise their MY GROOVE RADAR's CHAOS rating to 160, they would need to clear the chart with less than 72 Misses, assuming their CHAOS rating is above 144 already.