Value betting masterclass · Module 4: Football markets and the Value Predictor · Lesson 17 of 25 · About 6 min
In its most common form, a first half goals bet pays out if at least one goal goes in before half-time. Bookmakers call it “over 0.5 first half goals” or “goal in the first half”. It sounds simple, and happily the maths is simple too.
This guide explains why first halves produce fewer goals, how to turn expected goals into a fair price, and why our Value Predictor no longer includes this market.
Read the transcript
Over nought point five first-half goals wins as long as anyone scores before the break. Here's how to price it.
Around forty-five per cent of goals tend to come in the first half. So if a match has two point eight goals expected, you'd expect about one point two six of them before half-time.
That makes the chance of no first-half goal about twenty-eight per cent. So there's a seventy-one point six per cent chance of at least one, and a fair price of roughly one point four.
Offered one point four four, that's worth about three pence per pound in expected value. At one point three three, it slips to around minus five.
The Value Predictor used to cover this market. But prices were usually around one point two nine, which needs the bet to land about seventy-seven and a half per cent of the time just to pay its way. At prices that short, there's very little room for value, so we dropped it.
Short prices leave almost no room for value, so check the price first, and please bet responsibly.
Key points
- Over 0.5 first half goals pays if anyone scores before the half-time whistle, added time included.
- Across the top leagues, roughly 44% to 46% of goals arrive in the first half.
- The chance of at least one first-half goal is 1 − e−λ, where λ is the expected first-half goals.
- With 2.6 expected goals in the match, that is about 69.0%, giving fair odds of about 1.45.
How the market works
The over 0.5 line needs a single goal from either team by half-time. Stoppage time at the end of the first half counts, but a goal after the restart doesn’t, even in the 46th minute. Some bookmakers also offer over 1.5 first-half goals or a goal for a named team, but this guide sticks to the main line.
Because one goal is enough, the odds are usually short, often between 1.30 and 1.50, so small changes in price make a big difference to value. 1.36 implies 73.5%, for example, while 1.50 implies 66.7%. Our implied probability (Lesson 2 out of 25 in the Masterclass) guide shows how to work these out.
Why first halves are quieter
Goals aren’t spread evenly through a match. A three-season study of the Premier League, La Liga, Serie A and Ligue 1 found 44.9% of goals came before half-time and 55.1% after it (Alberti and others, Sport Sciences for Health, 2013). The split varies a little by league and season, so roughly 44% to 46% is a fair working range, and 45% makes a convenient round figure.
There are several likely reasons. Players tire after the break, so defences make more mistakes. A team that is trailing has to push forward, which opens the game up. Managers bring on attacking substitutes late on. And second halves usually have more added time.
Pricing a first-half goal
You need one number: λ, the expected goals in the first half. A simple way to get it is to multiply your expected total goals for the match by 0.45. The Poisson formula for no goals is e−λ, and the chance of at least one is everything else, so P = 1 − e−λ.
Worked example
Your model expects 2.6 goals in Newcastle v Tottenham, so the first-half share is 2.6 × 0.45 = 1.17 goals.
- Chance of no first-half goal: e−1.17 = 31.0%
- Chance of at least one: 100% − 31.0% = 69.0%
- Fair odds: 1 ÷ 0.690 = 1.45
Now check some prices. At 1.50, the expected value per £1 is 0.690 × 1.50 − 1 = +£0.035. At 1.36 it is 0.690 × 1.36 − 1 = −£0.06. So 1.36 is too short for your estimate, while 1.50 looks like value.
The calculator below checks any price. Enter your stake, the odds and your chance to see the expected value and edge.
Expected value calculator
How sensitive is the price?
Quite sensitive. This is how the chance changes with expected total goals, using a 45% first-half share:
| Expected total goals | First-half λ | Chance of a goal | Fair odds |
|---|---|---|---|
| 2.5 | 1.13 | 67.5% | 1.48 |
| 2.8 | 1.26 | 71.6% | 1.40 |
| 3.2 | 1.44 | 76.3% | 1.31 |
Switching from 45% to 44% or 46% moves the chance at 2.8 goals by less than one point. Your total goals figure matters far more than the split. For more on building and testing a fair price, see our fair odds (Lesson 3 out of 25 in the Masterclass) guide.
Where the model falls short
Poisson assumes goals arrive at a steady rate. In reality the opening minutes are often cagey, and a team that scores early may sit back. Some fixtures are deliberately tight in the first half too, such as a cup tie where neither side wants to concede. Use the model as a starting point and adjust for what you know.
Why the Value Predictor no longer covers first-half goals
The free Value Predictor used to list matches for a first-half goal. We removed the market because its prices are usually too short to offer value.
Worked example
A typical first-half goal price is around 1.29, which only adds up if the bet lands 1 ÷ 1.29 = 77.5% of the time. Bookmakers already build recent form into that price, so strong form on its own rarely clears the bar.
At prices that short, there is very little room for any bookmaker to be bigger than the real chance. The Value Predictor now covers over and under 2.5 goals, both teams to score and match result instead, and our guide to the betting markets we cover (Lesson 15 out of 25 in the Masterclass) explains why. You can still use the method above to price first-half goals yourself.
Short odds and swings
Short odds feel safe, but they aren’t. At 69%, you would expect the bet not to land roughly 3 times in 10, and runs of 3 or 4 bets without a winner will happen. Even a genuine edge here is thin, so it only shows over many bets. Value betting helps you judge a price, but it never promises a profit.
Related guides
- Drip feeding bets in-play: the maths (Lesson 19 out of 25 in the Masterclass)
- Over 2.5 goals: how to price the market (Lesson 16 out of 25 in the Masterclass)
- Expected value betting (Lesson 4 out of 25 in the Masterclass)
- Betting variance (Lesson 13 out of 25 in the Masterclass)
- Value betting explained (Lesson 1 out of 25 in the Masterclass)
Lesson 17 of 25 · Football markets and the Value Predictor
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