In competitive rhythm games, timing windows provoke strong opinions. Make them too loose, and top players bunch up at perfect scores. Make them too tight, and playing feels frustrating instead of musical.
When tuning Rhythmio, our goal was simple: reward precise rhythmic timing fairly, without letting combo multipliers distort who actually played better.
Here is how our 5-tier timing brackets work, how we calculate accuracy, and why combo bonuses have no place in our competitive rankings.
The 5 Judgement Tiers
Rhythmio evaluates each keystroke against the song audio clock using symmetrical millisecond offsets around the note’s target timestamp ($t_0$):
| Judgement | Timing Window | Score Weight | Accuracy Value | Visual Feedback |
|---|---|---|---|---|
| MAX | $\pm 16.0 \text{ ms}$ | $100%$ | $100%$ | Neon Cyan with pulse glow |
| PERFECT | $\pm 38.0 \text{ ms}$ | $85%$ | $85%$ | Crisp Gold |
| GREAT | $\pm 70.0 \text{ ms}$ | $55%$ | $55%$ | Emerald Green |
| GOOD | $\pm 105.0 \text{ ms}$ | $20%$ | $20%$ | Soft Slate / Blue |
| MISS | $> 105.0 \text{ ms}$ | $0%$ | $0%$ | Red / Combo Reset |
Why $\pm 16\text{ms}$ for MAX?
On a 60Hz display, one visual frame lasts about $16.67\text{ms}$. A $\pm 16\text{ms}$ threshold spans $32\text{ms}$ total, which is a standard benchmark in competitive vertical scrolling rhythm games.
Hitting a MAX judgement means striking within about one video frame of the musical beat. On high-refresh monitors (144Hz to 360Hz), this tight window gives immediate, crisp tactile feedback when your hands lock into the rhythm.
Pure Accuracy vs. Combo Weighting
Many older rhythm games scale note values with combo multipliers. Under that model, hitting a note at 500 combo yields far more points than hitting the same note at 10 combo.
That mechanic creates artificial tension, but it undermines fair competition:
- A player who drops note 10 but hits the remaining 990 notes with $99.8%$ accuracy ends up with a much lower score than someone playing sloppily at $91.0%$ who never broke combo.
- The match becomes a test of where you missed rather than how accurately you played throughout the song.
Rhythmio ranks players purely on accuracy:
$$\text{Accuracy (%)} = \frac{100 \cdot N_{\text{MAX}} + 85 \cdot N_{\text{PERFECT}} + 55 \cdot N_{\text{GREAT}} + 20 \cdot N_{\text{GOOD}}}{N_{\text{Total}}} \times 100%$$
The accuracy percentage shown on your results screen represents your true timing across the entire track. A slip on the first note and a slip on the final note carry the exact same weight.
Long Notes and Release Timing
Long notes test not just when you press down, but when you let go:
- Initial Strike: Evaluated against the standard 5-tier window when you press the key.
- Tick Holding: While the key stays down, tick events accumulate combo and maintain score credit.
- Release Window: Releasing too early or lingering past the tail incurs a penalty. Releasing within $\pm 45\text{ms}$ of the note end gives full credit.
This setup ensures that patterns with held notes on one finger and fast taps on another demand genuine finger independence.
Wrapping Up
A strict $\pm 16\text{ms}$ MAX bracket combined with transparent, combo-free scoring ensures that 1v1 duels and ranked placements reflect genuine timing ability.
In the next post, we explain why we chose the open web over building a desktop client.
