Introduction
The Groove Radar (グルーヴレーダー) is a pentagon-shaped marker that determines the difficulty of a song through five aspects: Stream, Voltage, Air, Freeze, and Chaos. The Groove Radar was introduced in DDRMAX -Dance Dance Revolution 6thMIX-. It appears in the Select Music screen, below the selected song's banner. As of DDR X2, it appears below the songwheel.
Before DDR SuperNOVA, Beginner charts had no Groove Radar data at all.
The Groove Radar has gone changes throughout the series's lifetime. Before DDR SuperNOVA2, the Groove Radar was colored fully with a lighter outline. However, as of DDR SuperNOVA2, the radar becomes more transparent towards the center.
The Five Values
Stream
Main article: Stream (Groove Radar)
Stream determines the overall density of the notes in a song's chart. The number of notes in the song and the length of the song (in seconds) contribute to determining this value.
Voltage
Main article: Voltage (Groove Radar)
Voltage determines the peak density of the notes in a song's chart. This is not referring to the fastest section of a song, but the section with the most notes packed on-screen (in any 4 consecutive beats). The average BPM of the song also plays a part in determining this value.
Air
Main article: Air (Groove Radar)
Air refers to the number of jumps in a song's chart and as of DDR X, also refer to the number of Shock Arrows in the chart in relation to the song's length.
Freeze
Main article: Freeze (Groove Radar)
Freeze depicts the total lengths of the Freeze Arrows (in beats) there are in a chart in relation to the total number of 4th beats in the song.
Chaos
Main article: Chaos (Groove Radar)
Chaos determines how many non-4th notes, or off-beat notes, there are in the chart. If there are BPM changes and/or stops, the Chaos value may increase. A main part of determining this value is the distance (in beats) each note is from the one before. Red (4th) notes have no Chaos value themselves.
My Groove Radar
In DDR SuperNOVA2 and later arcade installments, the player gets a Groove Radar status called My Groove Radar (マイグルーヴレーダー). There are two radars: one for Single Play (colored cyan), and one for Double Play (colored pink). As the player completes a song, their My Groove Radar values increase, up to a maximum of 200. The values increase by 10% of the values of the chart you played. For example, if you full combo Across the Nightmare on Expert (Voltage value of 100), then you will gain 10 for your Voltage value. Each time afterwards, you will earn 10% of what is left to completely achieve your desired value (on Across the Nightmare, the second time you full combo it, you will earn 9, the third time 8.1, etc). Each of the 5 values has its own way to get the maximum possible increase of a value. They will be explained in their respective articles.
They are also given a rank depending on the number of the Groove Radar value. There are 15 ranks:
| Rank | Minimum Value |
|---|---|
| Unknown | (All) 0 |
| Beginner | 0-9 |
| Warrior | 10-19 |
| Samurai | 20-29 |
| Knight | 30-39 |
| Noble | 40-54 |
| Shogun | 55-69 |
| King | 70-84 |
| Emperor | 85-99 |
| Dragon | 100-119 |
| Phoenix | 120-139 |
| Deity | 140-159 |
| God | 160-179 |
| Dazu God | 180-197 |
| True God | 198-200 |
With an eAMUSEMENT pass, you can access the My Groove Radar page in the Data Entry screen.
In DDR CS Releases
Wii series
The Groove Radar did not appear until DanceDanceRevolution HOTTEST PARTY 3. Like in the arcade versions, the selected difficulty will show its radar. In DDR II, the radars for all available difficulties are shown. The radar in DDR II has also undergone a new change in appearance: simple outline colored to a certain difficulty.