Set . For chordal Schramm–Loewner evolution, the centered image of a real boundary point, divided by , follows the Boundary-point Bessel flow for SLE; changing to matches the sign convention in the question. Thus and are the times at which the marked boundary points and are swallowed, or equivalently disconnected from infinity, by the Loewner chain.
Consequently
It is the event that the negative marked point is swallowed before the positive marked point.