1. REST vs WebSocket at a Glance

Think of REST as “What is the match state now?” and WebSocket as “What just changed?”

2. How REST Works for Live Table Tennis

With REST, your application sends a request whenever it wants the newest state.

GET /v1/table-tennis/matches/live

{
  "match_id": "match_tt_48291",
  "status": "live",
  "sets": {
    "player_a": 2,
    "player_b": 1
  },
  "current_set": {
    "number": 4,
    "player_a": 8,
    "player_b": 6
  }
}

If your application wants to know whether the score changes after that response, it sends another request later.

3. REST Polling Is Simple and Predictable

Polling means repeating the same request at a chosen interval.

let timer;

async function loadLiveMatches() {
  const response = await fetch('/api/live-table-tennis');

  if (!response.ok) {
    throw new Error(
      `Live request failed: ${response.status}`
    );
  }

  return response.json();
}

function startPolling() {
  timer = setInterval(() => {
    if (document.visibilityState === 'visible') {
      loadLiveMatches()
        .then(updateUI)
        .catch(console.error);
    }
  }, 15000);
}

Why developers like REST polling

• Simple request/response mental model
• Easy to test with normal HTTP tools
• Easy to retry after temporary failures
• Works naturally with caching
• Good fit for prototypes and MVPs
• Easy to load complete authoritative state

4. The Limitation of Polling Fast-Moving Matches

Table tennis can produce many score changes in a short period. Polling means your application may repeatedly download unchanged state while also missing the exact sequence of events between snapshots.

12:00:00 → GET score → 7-5
12:00:05 → GET score → 7-5
12:00:10 → GET score → 8-6
12:00:15 → GET score → 9-6
12:00:20 → GET score → 9-6

Two requests returned no new information. And although the state changed from 7–5 to 8–6, a state snapshot alone may not tell you the exact event sequence that occurred between those requests.

5. How WebSocket Streaming Works

A WebSocket connection stays open. After your application subscribes to a supported match or tournament, the provider can push events when the live state changes.

{
  "action": "subscribe",
  "channel": "table_tennis_match_events",
  "match_ids": [
    "match_tt_48291"
  ]
}

Then an event can arrive

{
  "event_id": "event_tt_90018",
  "match_id": "match_tt_48291",
  "type": "point_won",
  "sequence": 73,
  "set_number": 4,
  "player_id": "player_tt_101",
  "score": {
    "player_a": 8,
    "player_b": 6
  }
}

The application no longer has to ask whether that point happened. The event itself carries the change.

6. WebSocket Adds More Moving Parts

The trade-off is complexity. A persistent connection introduces concerns that ordinary REST clients do not need to manage continuously.

7. Which Is Faster for Live Updates?

WebSocket often feels faster because it removes the wait for the next polling interval.

Point happens
    ↓
Wait until next poll
    ↓
Request sent
    ↓
Response received
    ↓
UI updates

Point happens
    ↓
Provider publishes event
    ↓
Event delivered
    ↓
UI updates

That does not mean WebSocket guarantees a specific latency. End-to-end speed still depends on the original data source, provider processing, network transit, your backend and frontend rendering.

8. Measure the Full Data Path

A fast HTTP response can still contain old data. For live sports, the more useful metric is how long it took a real sports event to reach the screen.

provider_event_time
backend_received_time
backend_processed_time
frontend_received_time
frontend_rendered_time

provider_to_backend =
backend_received_time - provider_event_time

backend_processing =
backend_processed_time - backend_received_time

end_to_end =
frontend_rendered_time - provider_event_time

9. Bandwidth: Full State vs Incremental Events

REST polling may repeatedly transfer the same player, tournament, set and match fields even when only one point changed.

match
players
tournament
status
set history
current set
current points
timestamps
...

point_won
match_id
player_id
new score
sequence

Event-driven delivery can reduce repeated unchanged payloads, although the real bandwidth difference depends on event volume, polling frequency and the provider schema.

10. REST and WebSocket Can Have Different Cost Models

API cost is not determined only by bytes transferred. Providers may limit or bill different resources.

11. Do Not Let Every Viewer Poll the Provider

Imagine 10,000 users watching the same match. An inefficient architecture allows every browser to create its own upstream polling loop.

10,000 viewers
      ↓
10,000 independent polling loops
      ↓
Provider API

A much stronger model centralises provider access.

10,000 viewers
      ↓
Your application
      ↓
Shared live match state
      ↓
Controlled upstream polling
or
Shared WebSocket ingestion

One controlled upstream update can then serve thousands of viewers.

12. Do Not Open One Provider WebSocket Per Visitor

WebSocket can be implemented badly too. A persistent upstream connection for every visitor can create unnecessary pressure and expose connection details you would rather keep on the backend.

Provider WebSocket
       ↓
Connection Worker
       ↓
Validation + Deduplication
       ↓
Shared Match State
       ↓
Internal Pub/Sub
       ↓
Your WebSocket / SSE
       ↓
Viewers

Why this pattern scales better

• Controls upstream connection count
• Keeps provider credentials on the backend
• Centralises duplicate protection
• Creates one authoritative live state
• Lets many users share the same provider event
• Makes reconnect recovery easier to manage

13. REST Is Naturally Strong at Recovery

Every REST request can return the latest complete state. If your application loses connectivity, the recovery flow is straightforward.

Network restored
      ↓
GET /matches/{match_id}
      ↓
Receive authoritative state
      ↓
Render correct score

That simplicity is one of the biggest reasons REST remains valuable even in a WebSocket-heavy application.

14. WebSocket Needs Explicit Reconnect Logic

Do not assume every event was received while the connection was interrupted.

15. WebSocket Event Handling Must Be Idempotent

A point event can be retried, replayed or delivered again after reconnection. Your system must be able to see the same event twice without applying it twice.

processed_events

event_id        UNIQUE
match_id
sequence
event_type
processed_at

async function processEvent(event) {
  const exists = await eventStore.has(event.event_id);

  if (exists) {
    return;
  }

  await eventStore.save(event);
  await updateMatchState(event);
}

16. Sequence Numbers Help Detect Missing Events

If the production stream defines sequence values this way, the gap tells you that an event may be missing. The safe response is to reload authoritative match state through REST instead of guessing what happened.

17. The Strongest Production Pattern Is REST + WebSocket

The hybrid model lets each transport do the job it is best at.

Before match:
REST → fixture, players, rankings, H2H

At match start:
REST → full current match state

During match:
WebSocket → points, sets, status events

After disconnect:
REST → authoritative recovery

At match end:
REST → final result confirmation

This gives you the convenience of full-state queries and the responsiveness of event-driven live updates.

18. Use REST for Complete or Slow-Changing Data

19. Use WebSocket for Immediate Incremental Changes

20. Start With REST if You Are Building an MVP

WebSocket is valuable, but it introduces more infrastructure. If your first goal is to validate the product, REST polling plus a shared cache is often the fastest route to a working version.

MVP:
REST polling
Shared cache
Live match UI

Later:
Add WebSocket ingestion
Add event store
Add sequence tracking
Add reconnect recovery
Add internal fan-out

Upgrade when the product requirement actually needs push-based event delivery.

21. High-Traffic Products Benefit From Shared Event Ingestion

One provider point event can update one shared state object and then be distributed to thousands of users.

One point event
      ↓
Backend receives it once
      ↓
Shared match state updated once
      ↓
Thousands of viewers receive update

This is often more efficient than having every user independently ask the provider whether the score changed.

22. Your Frontend Does Not Need the Provider’s Protocol

Your backend can consume a provider WebSocket and expose updates to your users through your own WebSocket, Server-Sent Events or another transport.

Provider WebSocket
      ↓
Your backend
      ↓
Your internal WebSocket / SSE
      ↓
Browser or mobile client

This keeps authentication, upstream limits and provider-specific details out of the client application.

23. How to Choose Between REST and WebSocket

24. Production Checklist

• Keep permanent provider credentials on the backend
• Use REST for initial authoritative match state
• Use shared caching for repeated REST reads
• Do not poll the provider independently from every viewer
• Do not open one provider WebSocket per visitor
• Store unique event IDs
• Track sequence values where supported
• Detect stale WebSocket connections
• Reconnect using controlled backoff
• Reload REST state after uncertain connection gaps
• Confirm final match state after completion
• Measure provider-to-screen freshness
• Respect request, connection and subscription limits
• Confirm competition-level WebSocket availability

Common REST and WebSocket Mistakes

Frequently Asked Questions