Grade the Retest

A retest is a stress test of the breakout. Depth, speed and whether the old boundary held are the three things that separate a level being defended from one being slowly given up.

40% of the impulse
measured from the impulse high back toward the boundary
3 bars
how long price lingered before reacting

Did it hold the old boundary?

An honest limitation. The depth and speed thresholds here come from order-flow reasoning and trading practice, not from a measurement on our sample — treat them as a structured way to be consistent rather than as calibrated probabilities. What is measured: across 489 breakout attempts on 490 SPY sessions, 75% closed back inside the range within 30 minutes, and the median confirmed failure arrived in about four minutes. The retest window and the failure window are the same window.