The 1988 chapter names three competencies: diagnosing (sensing and appreciating differences in followers' abilities and motives and reading clues in the environment), adapting (having the flexibility and range to vary one's own behaviour to meet those demands) and communicating the chosen style so that followers understand and accept it; the expanded model is offered as a quick reference for all three. The Center for Leadership Studies now teaches a fourth, advancing: managing the movement toward higher performance by acting as a catalyst for development and a check on regression. Leadership is influence in any direction (down, up or across), and the model gives a shared language for performance conversations.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.