The most immediate consequence is the one Segal's senior engineer identified from the Trivandrum training room: the question of what the remaining twenty percent is worth. If the machine's approximation of architectural judgment is good enough for most purposes, the engineer's irreplaceability becomes conditional. He is irreplaceable for the hardest problems, the most consequential decisions, the cases where 'good enough' is not good enough. For everything else, the machine's approximation suffices.
This conditional irreplaceability has a corrosive effect on the human's sense of contribution. A partner needed only for the hardest problems is a partner whose contribution to routine work is marginal. The human in this position faces a specific psychological challenge: maintaining the cognitive investment that the hardest problems require while spending most of their time in a partnership where that investment is not needed. The analogy is to military combat readiness during long peace — the skills required for crisis developed through practice, and practice requiring engagement that the routine does not demand.
The failure mode is not dramatic collapse but quiet degradation. The human withdraws from routine direction. The machine's output determines more of the partnership's trajectory. The human evaluates less frequently, because evaluation feels less necessary — the machine's output is usually adequate. The evaluation muscle weakens through disuse. And the weakening makes the human less capable of detecting the cases where the machine's output is inadequate — the cases where the human's judgment is most needed and most valuable.
The asymmetry was implicit in Licklider's own concession about the interim — his acknowledgment that machines would eventually dominate cerebration alone. The Segal-Opus reading makes the intermediate condition explicit: not full machine dominance, but a progressive narrowing of the domains where the human's contribution remains unambiguously necessary.
Conditional irreplaceability. The human is essential for the hardest cases, marginal for the routine ones.
Readiness maintenance problem. Skills needed for crisis atrophy when routine doesn't exercise them.
Supervisor drift. The human becomes quality-control rather than co-creator.
Quiet degradation. The failure mode is not collapse but progressive erosion of evaluation capacity.
Institutional structures required. Individual willpower cannot sustain the discipline that asymmetric partnership requires.