Coaches carry repeatable tactical and results signatures that travel across clubs. These tendencies are more stable than individual player performance because they reflect deep-seated tactical philosophy and personality. Emery's third-season collapse, Glasner's abnormally high draw rate, Parker's systematic underperformance relative to squad quality, Moyes as a "competence amplifier" who elevates weak squads but can't push elite ones, Slot's immediate defensive transformation at every club — these are exploitable patterns. Building a database of coach tendencies across multiple tenures creates a predictive edge for betting and recruitment.
(1) For each manager, compile xG differential, points per game, and tactical metrics across ALL career tenures — not just the current one. (2) Identify which metrics are stable across clubs (these are the manager's signature) vs. which vary (these are squad-dependent). (3) Build a "manager tendency card" with stable signatures: defensive/attacking balance, draw propensity, performance trajectory by season (first-season boost vs. third-season fade), and response to European fixture load. (4) When a manager is appointed, project performance based on the tendency card + current squad quality. (5) Bet on the divergence between market expectations (driven by recency) and tendency-predicted outcomes.
Unai Emery has a documented pattern across Sevilla, PSG, Arsenal, and Villarreal where performance peaks in season 1-2 then collapses in season 3. This isn't random variance — it reflects a tactical approach that opponents decode and a motivational style that has diminishing returns. By season 3, the press patterns are scouted, the in-game adjustments are anticipated, and the dressing room dynamic shifts.
David Moyes consistently overperforms expectations at lower-quality squads (Everton, first West Ham stint) and underperforms at higher-quality ones (Manchester United, second West Ham stint after spending). His value is as a "competence amplifier" — he brings organization and defensive solidity to chaotic squads but lacks the tactical sophistication to maximize elite talent. Market odds tend to treat him as a single-quality manager regardless of squad level.
Arne Slot's defensive metrics improve within 5 matches at every club he manages. At Feyenoord, he inherited a leaky defense and immediately became one of the best defensive units in the Eredivisie. At Liverpool, the same pattern emerged. This is a genuine coaching signal, not squad quality — the players are the same, the defensive output changes immediately.