Evidence & Methods
Caveat — Hypothetical Research Plan
This research programme is a conceptual prototype. It outlines how Football State Language could be tested, validated, and operationalised, but it has not yet been reviewed, audited, or endorsed by experienced analysts, coaches, sport scientists, or research professionals within the football industry. All methods, definitions, and statistical plans should be treated as provisional and subject to revision following expert consultation, pilot studies, and formal methodological review.
FSL is better understood as a behavioural research framework for generating and testing football hypotheses than as a settled account of how football works. The pages on this site that read as confident — Vocabulary, Foundations — are offering a language to think with; this page is where that language is meant to be put under pressure.
1. Methods & Research Plan
FSL is a behavioural state model of football. A behavioural model must be observable, reliable, and falsifiable. This section describes how the 13-state architecture is tested in practice.
1.1 Coding System
FSL uses a structured coding system to classify each team's behaviour into one of thirteen states. Coders assign one primary state per team per minute, based solely on observable behaviour.
Coding unit: 1 minute
One primary state per team per minute
Transitions logged separately
Coders work independently and blind to outcome
Commentary muted during first pass
No tactical labels, reputation, or scoreline used in coding decisions
1.2 Data Sources
Behavioural observation — state labels coded from broadcast footage; transitions and player-level behaviours coded separately.
Quantitative match data — xG, event data, possession, tracking data (Phase 3), and player/squad data.
1.3 Research Phases
Phase 1 — Reliability & Feasibility: establish whether states are independently observable; test early hypotheses; κ ≥ 0.65 required to proceed.
Phase 2 — Predictive Tests: test whether state durations and transitions outperform conventional metrics.
Phase 3 — Player-Level Effects: test whether specific players influence team state stability or volatility.
1.4 Reliability Requirements
Minimum two independent coders per match
Disagreements resolved by a third coder
Per-match κ reported
Calibration on three designated matches before live coding
Coders must pass calibration (κ ≥ 0.65)
1.5 Sample Requirements
Phase 1–2 minimum: 60 matches
Full programme target: 150 matches
Estimated coded minutes at 60 matches: 5,400
1.6 Analysis Workflow
Preregister hypotheses and analysis plan.
Lock data sources.
Code matches independently.
Compute inter-coder reliability.
Resolve disagreements.
Merge coded states with xG and event data.
Run preregistered statistical models.
Report results, including κ values.
Revise definitions if needed.
Version the manual and proceed to next phase.
2. Formal Hypotheses (v1.0)
These hypotheses reflect the updated 13-state architecture. Each is stated in falsifiable form and preregistered before analysis.
H1 — Collapse precedes measurable xG deterioration. Teams entering Collapse will show a statistically significant decline in xG difference within the subsequent 5–15 minutes, compared to periods coded as Settle, Contain, Connect, or Command.
H2 — Functional stability outperforms possession. Total time spent in Settle + Contain + Connect will correlate more strongly with match outcomes (points, xG difference) than possession percentage.
H3 — Failure states produce tactical distortions. Periods coded as Fog, Drift, Stall, Scramble, or Overheat will show significant changes in spacing variance, pass tempo, pressing trigger distance, and defensive line height variance relative to functional states.
H4 — Functional transitions precede outcome events. Transitions such as Connect → Drive, Drive → Ignite, or Ignite → Slice will occur 2–6 minutes before major outcome events (goals, big chances, defensive errors) more often than expected by chance.
H5 — Low-variability attackers outperform high-variability attackers. Attackers with low self-variability in action patterns will generate higher xG per action than high-variability attackers, controlling for team strength and role.
H6 — State disruptors increase opponent volatility. When specific players are on the pitch, opponents will show increased frequency of Fog, Drift, Scramble, or Overheat, independent of tactics or scoreline.
H7 — Youth performance depends on functional stability. Youth-heavy lineups paired with a stable functional core (Settle/Contain/Connect) will outperform youth-heavy lineups without such stability.
H8 — Substitutions in failure states underperform. Substitutions made during Fog, Drift, Overheat, or Collapse will produce smaller positive impacts on xG difference than substitutions made during Settle, Connect, or Command.
H9 — Error cascades follow destabilising events. After a destabilising event (miscommunication, near-concession, emotional spike), secondary errors will increase significantly within the next 3–7 minutes.
H10 — Half-time state outperforms scoreline. The governing state at half-time will predict second-half xG difference and goals more accurately than the half-time scoreline.
3. FSL Coding Manual (v1.0)
Inter-coder reliability target κ ≥ 0.65 · Minimum coding unit: 1 minute · Version 1.0, June 2026
3.1 State Architecture
FSL defines seven functional states and six failure states. Functional states describe coherent, purposeful behaviour. Failure states describe breakdowns, malfunctions, or destabilisation. Full definitions of each state are given on the Vocabulary page; this manual assumes that vocabulary and adds the markers and decision rules used to apply it in practice.
3.2 Behavioural Markers
Behavioural markers are the observable cues a coder uses to assign a state. They are descriptive, not diagnostic — no single marker confirms a state alone; coders weigh the combination present in the interval.
Settle
Passing tempo slows; more sideways/backward passes than forward
Players re-form base shape; gaps between lines narrow
Marker applies regardless of opponent behaviour
Contain
Compact defensive shape; reduced distance between defensive lines
Limited forward passing options attempted; possession recycled safely
Deliberate reduction of tempo by the team without the ball
Connect
Short-to-medium passing combinations between 3+ players
Movement supports passing lanes (third-man runs, rotations)
Ball retention with clear directional progression
Drive
Increased forward passing tempo and vertical progression
Players advance beyond the ball; forward runs in numbers
More duels and press resistance without loss of shape
Ignite
Sudden acceleration in tempo or directness
Increase in risk-taking actions (through balls, dribbles, long shots)
Distinguished from Drive by suddenness
Slice
Line-breaking pass or carry removing an opposition line
Rapid combination through a previously closed space
Immediate shot/cross/chance within 1–2 actions
Command
Sustained territorial dominance with low turnover risk
Opponent reactive rather than pressing
The team in Command dictates tempo; the opponent reacts, the team decides.
Fog
Miscommunication (crossed runs, unclear calls)
Passing options available but unused
No clear directional intent
Drift
Spacing loosens without collapse
Possession slows without deliberate reason
Momentum and initiative fade
Stall
Possession retained but no forward options for 2+ passes
Receivers face backward/sideways with no forward option
Unintentional failure to progress
Scramble
Reactive, uncoordinated defending
Loss of defensive shape
High-intensity, low-structure actions
Overheat
Rushed decisions (forced passes, early shots)
Increase in unforced errors
High intensity with declining execution
Collapse
Breakdown in shape with no coordinated response
Individuals act without reference to teammates
Opponent gains large space/time advantages
3.3 Decision Rules
These rules resolve ambiguity when multiple states could plausibly apply.
Rule 1 — Primacy of the majority window. Code the state occupying >30 seconds of the minute. If none, code the state present at the end and flag as a transition minute.
Rule 2 — Functional vs. failure precedence. If both functional and failure markers appear, failure takes precedence. Failure states describe breakdown; functional states describe intact organisation.
Rule 3 — Minimum evidence threshold. A state requires at least two independent markers. If no state meets this threshold, code Fog.
Rule 4 — Adjacent-state disambiguation
Drift vs. Stall. Stall = Low Agency × High Clarity (options visible but not reachable). Drift = Low Agency × Low Clarity (no clear options). If a visible unused option exists → Stall; otherwise → Drift.
Contain vs. Stall. Contain = deliberate slowing. Stall = involuntary failure to progress. If intent cannot be read → default to Stall.
Overheat vs. Scramble. Overheat = team still has initiative. Scramble = team reacting to lost possession/opponent attack. Possession at interval start determines assignment.
Drive vs. Ignite. Sustained tempo increase (2+ intervals) → Drive. Single-interval spike → Ignite.
Provisional rule note: the three tie-breaks above are interpretive additions. Flag as provisional; revisit after Phase 1 pilot data.
Rule 5 — No outcome-based coding. Do not infer state from goals, shots, or scoreline changes. Code behaviour, not outcome.
Rule 6 — Disagreement resolution. A third coder resolves disagreements, blind to prior codings and outcome. Their judgement is final; disagreements logged for revision.
3.4 Transition Coding
Record outgoing and incoming states
Record trigger event (if observable)
Record trigger confidence (H/M/L)
Transitions must persist for 90 seconds to count
3.5 Coding Sheet Format
Field Format Primary state SET / CON / CNT / DRV / IGN / SLC / CMD / FOG / DRF / STL / SCR / OH / COL Confidence H / M / L Transition flag 0 / 1 Trigger Text Trigger confidence H / M / L
Foundations describes the behavioural model this manual is built to test. Vocabulary gives the plain-language version of every state named here.