Build a value betting bot in Python

What a value betting bot is, and is not

How the bot works

What you need

pip install requests

export VALUEODDS_BASE_URL="https://..."      # from your ValueOddsAPI account
export VALUEODDS_API_KEY="..."
export TELEGRAM_BOT_TOKEN="..."              # from @BotFather
export TELEGRAM_CHAT_ID="..."                # your own chat with the bot

python bot.py

The complete script

This is the whole bot, about 80 lines. The settings at the top are the ones to change: which bookmakers to scan, the minimum EV, the maximum price age, the odds range and the staking rule (half Kelly, capped at 3% of the bankroll).

import os
import sqlite3
import time
import requests

BASE = os.environ["VALUEODDS_BASE_URL"]
KEY = os.environ["VALUEODDS_API_KEY"]
TG_TOKEN = os.environ["TELEGRAM_BOT_TOKEN"]
TG_CHAT = os.environ["TELEGRAM_CHAT_ID"]

REFERENCE = "pinnacle"
SOFT = ["bet365", "unibet", "betano"]
MIN_EV, MAX_AGE = 0.02, 10          # +2% or better, prices at most 10 s old
MIN_ODDS, MAX_ODDS = 1.50, 5.00
BANKROLL, KELLY_FRACTION, MAX_STAKE = 1000, 0.5, 0.03

db = sqlite3.connect("value_bets.db")
db.execute("""CREATE TABLE IF NOT EXISTS alerts (
    bet_key TEXT PRIMARY KEY, bookmaker TEXT, odds REAL, fair_odds REAL,
    ev REAL, stake REAL, alerted_at INTEGER, closing_odds REAL)""")

def fetch(bookmakers):
    r = requests.get(f"{BASE}/v1/odds",
                     params={"phase": "prematch", "bookmakers": ",".join(bookmakers)},
                     headers={"Authorization": f"Bearer {KEY}"}, timeout=10)
    r.raise_for_status()
    return r.json()["data"]

def same_bet(row, outcome):
    m = row["market"]
    return (row["event_id"], m["id"], m["period"], m["line"], m["settlement"], outcome["id"])

def kelly_stake(odds, p):
    f = (odds * p - 1) / (odds - 1) * KELLY_FRACTION
    return round(BANKROLL * min(f, MAX_STAKE), 2)

def alert(text):
    requests.post(f"https://api.telegram.org/bot{TG_TOKEN}/sendMessage",
                  json={"chat_id": TG_CHAT, "text": text}, timeout=10)

def scan():
    rows = [r for r in fetch([REFERENCE, *SOFT])
            if r["market"]["status"] == "open" and r["data_age_seconds"] <= MAX_AGE]
    fair = {same_bet(r, o): o["fair_probability"]
            for r in rows if r["bookmaker"] == REFERENCE and r["market"]["fair_status"] == "available"
            for o in r["market"]["outcomes"]}
    found = new = 0
    for r in rows:
        if r["bookmaker"] == REFERENCE:
            continue
        for o in r["market"]["outcomes"]:
            p, odds = fair.get(same_bet(r, o)), o["bookmaker_odds"]
            if p is None or not MIN_ODDS <= odds <= MAX_ODDS:
                continue
            ev = odds * p - 1
            if ev < MIN_EV:
                continue
            found += 1
            key = "|".join(map(str, same_bet(r, o) + (r["bookmaker"],)))
            stake = kelly_stake(odds, p)
            cur = db.execute("INSERT OR IGNORE INTO alerts VALUES (?,?,?,?,?,?,?,NULL)",
                             (key, r["bookmaker"], odds, round(1 / p, 3), ev, stake, int(time.time())))
            if cur.rowcount:                # first time we see this bet: send it
                new += 1
                alert(f'VALUE {ev:+.1%} | {r["event_id"]} {r["market"]["id"]} {o["id"]} '
                      f'{r["market"]["line"] or ""}\n{r["bookmaker"]} {odds:.2f} vs fair {1 / p:.2f} '
                      f'| stake {stake:.2f} | price age {r["data_age_seconds"]:.0f}s')
    db.commit()
    print(f"{time.strftime('%H:%M:%S')} scanned {len(rows)} rows | {found} value bets | {new} new alerts")

while True:
    try:
        scan()
    except requests.RequestException as e:
        print("fetch failed, retrying:", e)
    time.sleep(15)

Running it

Measuring whether the bot works

def record_closing(bet_key, closing_odds):
    """Store the last price before kick-off for a bet the bot alerted."""
    db.execute("UPDATE alerts SET closing_odds = ? WHERE bet_key = ?", (closing_odds, bet_key))
    db.commit()

# Average raw CLV of everything the bot has flagged so far
avg_clv = db.execute("SELECT AVG(odds / closing_odds - 1) FROM alerts "
                     "WHERE closing_odds IS NOT NULL").fetchone()[0]

This is raw CLV. For the stricter, margin-free version, see Closing line value.

Making it production-ready

Estimate how many requests your setup needs with the request calculator, and read the integration guide.

Common mistakes in betting bots

Frequently asked questions

Related reading