Sports Betting Arbitrage

About the Project

An automated sports betting arbitrage detection system that scans live odds across multiple bookmakers to identify guaranteed profit opportunities (sure bets).

Overview

I became interested in sports betting arbitrage, also known as sure bets, where you place bets on all possible outcomes across different bookmakers in order to guarantee a profit.

I enjoy searching for "exploits" in systems that allow extracting guaranteed profit from inefficiencies. However, doing this manually is practically impossible, since it requires processing massive amounts of live data and performing calculations continuously. Because of this, I decided to automate the entire process and build a system that scans for these opportunities automatically.

Collecting Odds Data

I started by scraping live odds from multiple bookmaker websites.

One of the main challenges was that each bookmaker structures their events and betting markets differently. In order to compare odds across platforms, all of this data needs to be transformed into a single unified structure.

Another important aspect is handling different betting lines. For example, an Over/Under market might exist with lines such as 3.5, 4.5, or 5.5. These must be stored clearly and consistently so they can later be compared correctly. You cannot compare an Over/Under 3.5 with an Over/Under 4.5 when searching for arbitrage opportunities.

Event Matching

Another key problem is matching the same event across different bookmakers. Since naming conventions vary between platforms, events must be linked together before odds comparisons can be performed.

Odds Data Structure

After normalization, the odds data is stored in a unified JSON structure:

[
  {
    "event_name": "...",
    "sport_category": "...",
    "bookmakers": [
      { "name": "unibet", "event_url": "...", "stats": "...", "markets": [...] },
      { "name": "bet777", "event_url": "...", "stats": "...", "markets": [...] },
      { "name": "betcenter", "event_url": "...", "stats": "...", "markets": [...] }
    ],
    "home_team": "...",
    "away_team": "...",
    "start_time": "..."
  }
]

This unified structure makes it easy to scan across bookmakers for arbitrage opportunities.

Supported Markets

My odds screener currently supports the following betting markets:

• Match Winner (2-way and 3-way)
• Double Chance
• 1st & 2nd Goal Winner
• Set Winners (Tennis)
• Both Teams to Score
• Draw No Bet
• Half-time & Full-time Markets
• Handicap Betting
• Over/Under Markets (0.5 to 6.5 goals)
• Even/Odd Markets
• First & Second Half Over/Under
• Sets Over/Under (Tennis)

Arbitrage Detection

Once the odds screener was finished, the majority of the work was done. The data collection and normalization pipeline is by far the most complex part of the system.

Using Flask, I built a small dashboard where arbitrage opportunities can be monitored in real time.

When calculating arbitrage bets, you also have to consider stake rounding. For example, placing a bet of €20.45 on a bookmaker can raise suspicion and potentially get your account flagged. Bookmakers actively try to detect arbitrage bettors, so the system attempts to keep stake sizes as natural as possible.

The odds screener is designed to scan both live betting markets and pre-match events, continuously looking for profitable arbitrage opportunities.