Is this week a regime change or a headfake? What's your earliest signal?

My crude framework, please attack:

Trending — higher lows, breadth confirms, vol contained. Breakouts get respect.
Chop — open strength fades, rotation without follow-through. Breakouts trap.
Stress — vol expanding, breadth deteriorating, yields hostile. Size down, opinions stop mattering.

My problem: transitions. My journal says I recognize regime changes 3–5 days late. When I call them early, I get whipsawed.

So:

Classify the current market — and what evidence would change your mind?
If you could keep only ONE input to classify regime, which one?
When the regime flips: change strategy, or just change size?