B Baseline.
Baseline is the first BEARINGS letter. It lives inside S Situation and covers two worksheets — the ones that together establish what the program is actually solving before anyone picks a solution.
Purpose
A program that skips Baseline invariably ends up re-planning mid-delivery because the problem wasn't what people thought it was. Baseline forces the situation to be described in concrete terms (with evidence) and the root cause to be isolated (with structured questioning) so the rest of SAGE has a solid footing.
Worksheets
Where it fits
Baseline is the only BEARINGS letter inside the Situation phase. Engagement — the next letter — begins once Situation transitions to Assess, because stakeholder analysis is a planning activity, not a problem-framing one.