Do Bookmakers Overprice Favorites?

Author: Donald Micheal, Football Data Analyst 

Date: 22nd December 2025 

Introduction

Football fans and bettors have had this debate for the longest time - are favorites truly worth backing. 

It is easy to suggest that favorites should be tipped to win. Even bookmakers hold the same opinion. But then are they not consistently overvalued or are the markets pricing them the right way? 

This article aims to answer this question and settle what needs to be answered. We took into account 48,000 matches from 2015 to 2025 across all of Europe’s top leagues before we came to our conclusions. 

You can be sure that the ideas we are sharing are made from deep research and made to be accurate. 

In doing the research, we evaluated whether the feeling that the favorites will win is often because of the odds and then we tried to see if trends influenced market efficiency over the years. 

Data Sources

• Matches: 48,000 league matches

• Leagues: Premier League (England), Bundesliga (Germany), La Liga (Spain), Serie A (Italy), Ligue 1 (France)

• Seasons: 2015/16 – 2024/25

• Data Points: Home, draw, away odds; actual match result

Odds were taken during closing markets and we did that to ensure that we weren’t mistakingly drawing feedback from early market activity. 

Methodology

This is how HelloPredict analyzed the data that was set before us. First, we 

Converted Odds to Implied Probabilities

To convert the odds to implied probabilities, we use a simple equation like this: implied probability = 1/odds 

Because we wanted to reduce the bookmaker's overround, the probabilities were normalized. 

This normalization meant that the home + draw + away = 1. 

Identify Match Favorites

For us to identify, the match favorites, it was to determine the outcome that has the highest implied probability. 

Some times this can be the home team and it can also be the away team. 

There are other times where the draw market is the highest implied probability. This usually happens when there are low favorites. 

Compare Expected vs Actual

The next thing we did for each match was to compare the actual outcome that happened in the match against the expected outcome. 

If we see that the favorite won, we assign a score of 1, but if they lost, we assign 0. 

Aggregate by Favorite Strength

Then we grouped matches based on how the favorite’s implied probability was. For those who were moderate favorites, it was 55-64% implied chance, the strong favorites had a 65% - 74% implied win chance, and the very strong favorites had ≥75% implied win chance.

Measure Deviation

Next, we measured the deviation that is how far was the expected outcome different from the actual outcome. 

Deviation (%) = Actual Win Rate − Expected Win Rate

Results

1. Overall Favorite Performance

The table below shows how the favorites performed based on our analysis and findings:

From the data that you can see above, it is clear that the stronger the favorite, the weaker they will perform.

2. League Breakdown

We also had a breakdown of the leagues because they are different in expectations each time. 

These were our findings:

What we observed here is that no league overvalues favorites more than others and then deviations are modest and they are consistent around the top leagues. 

3. Trends Over Time

From a line chart, plotting the performance of favorites by seasons, we saw that there was a slight increase in the way these favorites underperformed over time and it became even higher during the 2020-2021 season.

We discovered that the possible causes of these underperformance was largely due to COVID19, fixture congestion, the need for squad rotation, and tactical changes. 

4. Upsets Are Most Common for Very Strong Favorites

We found that the strong favorites those who were estimated to have >75% implied win chance faced the highest rate of upsets. Clearly because they approached matches with overconfidence, had injury issues, or tried to rotate their squad. 

The moderate favorites were found to stay closer to the expected outcomes than any other team category. 

Key Insights

1. We found that markets are efficient because most deviations are just 3% - 4% which is great for large scale betting. 

2. Extreme favorites are really overvalued as they usually underperform their implied win rate by nearly 4%. 

3. There is no league that is completely different as every league follows the same pattern as regards market behavior. 

4. Bettors need better strategies as just going for extreme favorites may not always yield expected returns - the smaller favorites are the ones closer to providing any form of value. 

Limitations

There are certain limitaions with our study and they include:

1. Cup competitions were not analyzed - we only looked into league matches 

2. The odds did not take live/in-play betting

3. We did not include external factors like injuries to key players, the weather, and refereeing decisions. 

Conclusion

For over a decade, European football data has shown that bookmakers are slightly overpricing very strong favorites. 

The difference is not much but betting on moderate favorites has shown that they get closer to the actual outcomes. 

This analysis have proven that while betting markets are efficient, there are small margins of errors that can be costly. 

Nonetheless, betting is uncertain and the insights from prediction sites and platforms are supposed to inform analysis and not to guarantee outcomes.