Why Underdogs Win More Than You Think

Every prediction game has the same problem. People pick the favourites, week after week, and then act surprised when Nottingham Forest beat Manchester City or Bournemouth put three past Arsenal. These results are not freak accidents. They happen regularly, and if you are not accounting for them, you are leaving points on the table.

The word 'upset' makes underdog wins sound exceptional. They are not. They are a feature of the Premier League, built into the structure of the competition. And understanding how often they happen - and why - gives you a real edge in any prediction league.

How often do underdogs actually win?

Let us define terms. An 'underdog' here means a team from the bottom half of the table playing against a team from the top half. Using data from the last ten Premier League seasons, the numbers are clear.

• Bottom-half teams win roughly 22-25% of matches against top-half opposition
• That figure rises to around 28-30% when the bottom-half team is playing at home
• Away from home, bottom-half teams still win about 15-18% of the time against top-half sides
• Draws account for another 25%, meaning the favourite only wins about 50-55% of these fixtures

Read that last point again. When a top-half team faces a bottom-half team, the favourite wins barely half the time. The other half of the time, it is a draw or an upset. That is a massive chunk of results that most predictors just ignore.

Why favourites lose more than expected

Home advantage is still powerful

This is the single biggest factor behind underdog wins. A team sitting 16th in the table is a different proposition at home compared to away. Their crowd lifts them, they know their pitch, and they play with more confidence. When you see a bottom-half team hosting a top-six side, do not automatically hand three points to the visitor.

We covered this in detail in our piece on how home advantage shapes predictions. The short version: home teams win about 46% of all Premier League matches, regardless of league position. That alone should make you cautious about backing away favourites.

Fixture congestion and squad rotation

This is where the calendar becomes your friend as a predictor. Top teams in the Champions League or Europa League play midweek European matches, domestic cups, and then have a league game at the weekend. That is three matches in seven or eight days, and the fatigue is real.