The Guitar Accuracy Trainer is designed to help you develop precise timing in your playing by measuring how accurately you can match a metronome beat.

How It Works

Setup: You select a tempo (BPM), difficulty level, and duration
Countdown: The metronome gives you 3 seconds to prepare
Recording: Your playing is analyzed in real-time against the metronome
Analysis: After your session ends, the system calculates your accuracy score

Difficulty Levels

Each difficulty level uses a different timing window to determine what counts as “accurate”:

Brutal: For advanced players (±3% timing window). If playing at 120 BPM, each beat occurs every 500 milliseconds. A 3% window means your pick must land within ±15ms of the exact beat (3% of 500ms).
Human: For intermediate players (±10% timing window). At 120 BPM, you must land within ±50ms of the exact beat (10% of 500ms).
Forgiving: For beginners (±20% timing window). At 120 BPM, you must land within ±100ms of the exact beat (20% of 500ms).

How This Scales with Tempo

The timing windows adjust automatically based on the tempo you select:

At faster tempos (higher BPM), the windows get smaller in absolute time because the beats are closer together.
At slower tempos (lower BPM), the windows get larger in absolute time because the beats are further apart.

For example:

BPM	Beat Interval	Brutal (±3%)	Human (±10%)	Forgiving (±20%)
60	1000ms	±30ms	±100ms	±200ms
120	500ms	±15ms	±50ms	±100ms
180	333ms	±10ms	±33ms	±66ms
240	250ms	±7.5ms	±25ms	±50ms

This approach ensures that the difficulty scales appropriately with tempo – maintaining consistent challenge levels regardless of speed.

This also means that with a slow beat and easy difficulty, it’s really easy to get high scores.

How Scoring Works

Your accuracy percentage is calculated based on how closely your picking aligns with the metronome beats:

Scoring Breakdown by Difficulty

Perfect Timing Windows

Perfect timing earns bonus points when you hit within these tight windows:

Brutal mode: Within ±8ms (earns 30% bonus)
Human mode: Within ±25ms (earns 10% bonus)
Forgiving mode: Within ±50ms (earns 5% bonus)

Good Timing (Within Difficulty Window)

Hits within the main difficulty window earn points proportional to their accuracy:

Brutal mode: Within ±15ms at 100 BPM (full points)
Human mode: Within ±50ms at 100 BPM (full points)
Forgiving mode: Within ±100ms at 100 BPM (full points)

Early/Late Hits (Partial Points)

When you’re outside the perfect window but still within the difficulty window:

Brutal mode: If you’re 10ms off at 100 BPM, you earn about 67% of the points
Human mode: If you’re 35ms off at 100 BPM, you earn about 70% of the points
Forgiving mode: If you’re 80ms off at 100 BPM, you earn about 60% of the points

Missed Beats

If your hit falls outside even the maximum timing window for your difficulty level, it’s considered a miss and earns 0 points.

Example Calculation (120 BPM, Brutal Mode)

You play 30 beats total
10 beats are perfectly timed (within ±8ms) = 10 × 1.3 = 13 points
15 beats are within the timing window but not perfect = ~12 points (varies based on exact timing)
5 beats are missed completely = 0 points
Total raw score: 25 points out of 30 possible = 83.3%
Brutal mode adjustment: 83.3% × 0.75 = 62.5% final score

The final difficulty adjustments (Brutal × 0.75, Human × 0.9, Forgiving × 1.2) ensure that scores are meaningful across different skill levels, making the Brutal mode a true challenge while keeping the Forgiving mode encouraging for beginners.

Results Breakdown

The results page shows:

Your overall accuracy percentage
A timing graph showing each beat’s accuracy (green for perfect, blue for early, orange for late)
Your progress over time in the history graph
Your current practice streak

Timing Analysis

The timing graph helps you identify patterns in your playing:

Consistently early or late hits may indicate rhythmic tendencies you can work on
Scattered results might suggest general timing inconsistency
Perfect hits in specific sections show where your timing is strongest

Improving your score on the same tempo and difficulty over time is a clear indication that your timing precision is developing.