Balanced (1.0)

Balanced Behavior (snapEagerness: 1.0) - Default

Configuration: { snapEagerness: 1.0 } or simply naturalStickyTop(element)

This is the recommended default value that balances natural movement with gap prevention through subtle scroll prediction.

🎯 Why This is the Default

After extensive testing across different browsers, devices, and user behaviors, snapEagerness: 1.0 emerged as the sweet spot:

• ✅ Natural feel preserved: Movement still feels connected to your scrolling
• ✅ Gap prevention: Eliminates most visual artifacts without being intrusive
• ✅ Cross-browser reliability: Works consistently across all modern browsers
• ✅ Mobile-friendly: Handles momentum scrolling gracefully
• ✅ Performance optimized: Minimal prediction overhead

📐 The Prediction Algorithm

Here's how the one-step prediction works in the source code:

const handleScroll = () => {
  const currentScrollY = window.scrollY;
  const elementRect = element.getBoundingClientRect();
  
  // Calculate scroll velocity (distance moved this frame)
  const scrollVelocity = currentScrollY - lastScrollY;
  
  // Predict where the element will be after one more scroll step
  const predictedTop = elementRect.top - snapEagerness * scrollVelocity;
  //                                      ↑
  //                            snapEagerness: 1.0 = predict 1 step ahead
  
  // Switch to sticky when prediction shows element would be at/past top
  if (mode === 'relative' && predictedTop >= 0) {
    mode = 'sticky';
    element.style.position = 'sticky';
    element.style.top = '0';
  }
}

🔬 Technical Deep Dive

The magic happens in the prediction calculation:

• Scroll Velocity: currentScrollY - lastScrollY gives us the distance moved in this frame
• Prediction: elementRect.top - 1.0 * scrollVelocity estimates where the element will be next frame
• Decision Point: When predicted position ≥ 0, we know the element is about to reach the top
• Smooth Transition: Switch to sticky mode just before the gap would appear

🚀 When to Use the Default (1.0)

This balanced approach is ideal for:

• General-purpose applications - Works well for most use cases
• Mixed device targeting - Handles both desktop and mobile gracefully
• Unknown user behavior - Accommodates both slow and fast scrollers
• Production applications - Battle-tested reliability
• When in doubt - Safe choice that rarely disappoints

📱 Mobile Optimization

The 1.0 value is specifically tuned for mobile momentum scrolling:

• Handles the initial fast scroll phase
• Adapts during the deceleration phase
• Prevents gaps during quick flick gestures
• Maintains natural feel during slow drag scrolling

🔍 Testing This Configuration

Try these specific scroll patterns to see the balanced behavior:

• Slow scrolling: Should feel perfectly natural, just like 0.0
• Medium speed: Notice the smooth transitions with no gaps
• Fast scrolling: Prediction prevents gaps while maintaining connection
• Direction changes: Quick reversal should be handled smoothly
• Mobile flick: (If on mobile) Try momentum scrolling in both directions

📊 Comparison with Other Values

Understanding where 1.0 fits in the spectrum:

• snapEagerness: 0.0 - Pure natural (may show gaps)
• snapEagerness: 1.0 ← You are here (Balanced default)
• snapEagerness: 2.0 - More aggressive gap prevention
• snapEagerness: 3.0 - Intentional "magnetic" snapping effect

⚡ Performance Characteristics

The balanced approach offers optimal performance:

• Minimal CPU overhead: Single-step prediction is computationally light
• Smooth frame rates: No complex calculations per scroll event
• Memory efficient: Simple state tracking without history buffers
• Battery friendly: Especially important for mobile devices

Continue scrolling to experience how this balanced approach handles various scroll patterns. The goal is for the behavior to feel so natural that you don't think about it - the header should just "work" the way you expect.