A fourth official raises a substitution display during a daylight football match

Interactive product demonstrator

The reliable pitchside endpoint for every change.

Receive or enter the authorised substitution. Let the fourth official verify it. Display it unmistakably. Keep working if every connection fails.

Interactive product demonstrator · physical engineering and match validation required

Discuss engineering or competition testing →

THE PHYSICAL LAST STEP

Digital substitution information still needs a reliable pitchside display.

Team and match systems are becoming more digital. The final public action remains physical: the fourth official verifies the change and raises a board that players must see instantly from across the pitch.

Smart Substitution explores how structured match information, deliberate official confirmation and a rugged public display could operate as one fail-safe system.

DESIGNED TO COMPLEMENT

Digital requests need a dependable display endpoint.

FIFA’s substitution tablet demonstrates the move from paper requests towards structured digital substitution information. Smart Substitution explores a complementary physical role: how an authorised change could be checked by the fourth official and displayed clearly and reliably at pitchside.

Smart Substitution is not affiliated with, approved by or integrated with FIFA.

Read about FIFA’s substitution tablet →

COMPLETE WORKFLOW

One change. Five controlled stages.

01

TEAM REQUEST

A team official requests a change through the competition’s authorised procedure.

Integration concept

02

MATCH SYSTEM

The named squad and substitution request are checked against authorised match information.

Integration concept

03

FOURTH OFFICIAL

The outgoing and incoming players are deliberately verified.

04

PITCHSIDE DISPLAY

Only enormous red and green shirt numbers remain visible when the device is raised.

05

EVENT CONFIRMATION

Compatible authorised systems may receive confirmation that the change was displayed.

Integration concept

THE TWO-SIDED DEVICE

When raised, it is a display—not a tablet.

The official-facing rear holds the squad grid and confirmation controls. The pitch-facing front shows only enormous numbers on black.

Two-sided Smart Substitution development device with giant red 17 and green 24

OFFICIAL WORKFLOW

Verify the change. Then reveal only what the pitch needs.

Fictional match demonstration · Northbridge FC

Official-facing rearLocal mode · Batt 86%

Step 1 · Select player leaving

OUT

—

IN

—

Interactive product demonstrator—not match equipment. A substitution must never depend entirely on Wi-Fi, a remote server or a touchscreen.

WORKFLOW COMPARISON

Test the interaction, not the assumption.

EXISTING KEYPAD WORKFLOW

Manual number entry · familiar physical controls

Interaction target · not yet validated

0.0 sec

00

ENTER SHIRT NUMBER

  • Some boards support pre-programmed changes.
  • Established visibility and ruggedness.

Speed is a validation metric, not the case for the product. The target will be tested against manual entry and pre-programmed professional boards alongside correction rate, operator confidence and recovery after failure.

SMART SUBSTITUTION WORKFLOW

  • Fewer transcription errors between request and display
  • Verified authorisation before anything is shown
  • Clear queue management for multiple changes
  • Continued operation after connection loss
  • One consistent match-event workflow
  • Potential auditable event record
Development comparison between an established keypad board and rear squad-selection interface

Existing professional boards already store multiple pre-programmed changes. The development question is whether verified squad selection reduces transcription errors and recovery time without sacrificing their proven reliability. Full engineering requirements and the test protocol are on the validation page.

THREE OPERATING MODES

Future integration mode

CONNECTED MODE

  • Receives an authorised match squad
  • Receives or loads a requested substitution
  • Fourth official verifies both players
  • Display shows the confirmed numbers
  • Compatible systems may receive an event confirmation

Development workflow

STANDALONE MODE

  • Squad loaded locally
  • Official selects outgoing and incoming players
  • No stadium or broadcast connection required
  • Board remains fully operational

Engineering requirement

FAILURE MODE

  • Manual shirt-number entry
  • Recessed physical confirm and cancel controls
  • Display remains available
  • Replaceable backup power
  • No connection required

A substitution must never depend entirely on Wi-Fi, a remote server or a touchscreen.

MULTIPLE SUBSTITUTIONS

Prepare the sequence before the board goes up.

IFAB’s time-limited substitution procedure increases the importance of avoiding unnecessary delay between multiple changes. Formal compliance must be tested with officials and competition organisers.

Changes prepared · 3

17 → 24Current

R. Vale → T. Mercer

09 → 19Next prepared

S. Thornhaven → N. Ashfell

06 → 14Next prepared

P. Ellerby → J. Ravensmoor

1724

DEVELOPMENT STATUS

Interactive product demonstrator—not match equipment.

INTERACTIVE

  • — Official-facing squad-selection demonstration
  • — Pitch-facing display simulation
  • — Keypad comparison
  • — Multiple-substitution workflow
  • — Manual fallback demonstration

TO BE ENGINEERED

  • — High-brightness physical display
  • — Rear control surface
  • — Enclosure
  • — Physical controls
  • — Power system
  • — Connectivity

TO BE VALIDATED

  • — Matchday workflow
  • — Visibility
  • — Weather and impact resistance
  • — Battery endurance
  • — Competition acceptance
  • — Stadium and broadcast integrations

Competition acceptance, equipment compliance and integration requirements must be established for each intended deployment.

Professional development may require assessment of electrical safety, battery safety, electromagnetic compatibility, radio equipment, environmental protection, impact resistance and relevant UKCA/CE obligations.

Smart Substitution does not currently claim certification, competition approval or match authorisation.

THE OPPORTUNITY

Modernise the endpoint without weakening what already works.

Existing boards provide proven visibility and simplicity. Digital match systems provide structured information. Smart Substitution explores a dependable connection between them, designed around official verification, enormous public numbers and physical fallback.

PROBLEM

Substitution information may be entered or communicated through separate systems under match pressure.

PRODUCT

A two-sided physical endpoint built around verification and visibility.

DEFENCE

Engineering reliability, competition acceptance, system integration and manufacturing relationships—not the touchscreen alone.

NEXT MILESTONE

Build and test one functional two-sided prototype with match officials.

Discuss the prototype programme