Soccer Analytics

Podcast: Michael Caley on soccer analytics

Michael Caley, soccer analytics expert and co-host of the Double Pivot podcast, joins me for a wide ranging discussion. His writing has appeared on FiveThirtyEight, The Athletic, and The Correspondent.

Among other topics, we discuss:

The surprising Ph.D. that he earned before getting into soccer analytics (2:17)
Expected goals (xG) and future frontiers in soccer analytics (9:47)
The excruciating process that goes into calculating expected goals (18:55)
The Champions League prospects for Bayern Munich (20:20)
The best goal scorers in the game by xG (22:45)
How good is Liverpool? (25:39)
Is there any hope for USMNT? (27:29)

To listen here, click on the right pointing triangle:

To listen on Apple Podcasts, click here.

The Football Analytics Show is also available on Spotify and Google Podcasts.

Win probabilities for the 2015 Gold Cup

By Dr. Ed Feng Leave a Comment

Can the United States win the 2015 Gold Cup?

Winning the Gold Cup means more than than just bragging rights over rival Mexico. With the win, the United States qualifies for the Confederations Cup in 2017, a key tune up tournament for the World Cup in 2018.

If another team wins the Gold Cup, they play a one game playoff against the United States, winner of the 2013 Gold Cup. The winner of this playoff represents North America at the Confederations Cup.

To determine win probabilities for the Gold Cup, I combined three different estimates into an ensemble prediction. Two came from my own calculations that rank international teams on offense and defense (see the bottom of this article), and a third came from the markets.

The Gold Cup usually comes down to the United States and Mexico, but Costa Rica has emerged as a solid third team that made the final 16 of the World Cup last summer.

Let’s look at these three top contenders. The offense and defense rankings come from The Power Rank algorithm and use international matches since January 1st, 2011.

United States

12th offense, 27th defense

The United States looked fantastic in beating Germany in a friendly last month, and they also beat the Netherlands in another friendly. Both matches took place on European soil.

They need to play well at the start of the Gold Cup as their group has Honduras and Panama, two top 50 teams in my world soccer/football rankings. Meanwhile, Mexico has the dregs of CONCACAF (Guatemala, Trinidad and Tobago, Cuba, all ranked lower than 80th) in their group.

Coach Jurgen Klinsmann left central defender Matt Besler, who started every game of last year’s World Cup, off the Gold Cup roster. John Brooks will most likely start, and let’s hope they can improve a defense that has ranked 27th in the world over the last 4 years.

Mexico

11th offense, 9th defense

By the numbers, Mexico has a slight edge on the United States in my rankings. They don’t have the largest win probability though since the United States will enjoy home field advantage.

I’m not 100% certain the United States should get the full .59 goals for home field. If the United States and Mexico meet in Philadelphia for the final, there will be plenty of Mexican fans wearing green in attendance.

In my ensemble calculations, the market predictions most likely account for the semi-neutral type final in Philadelphia. They gave United States a 38% win probability with Mexico at 36%. The gap was bigger in my two calculations.

For Mexico, striker Javier “Chicharito” Hernandez broke his collar bone and will miss the Gold Cup. He scored 9 goals in 33 matches for Real Madrid last season.

Costa Rica

40th offense, 10th defense

Costa Rica had an amazing World Cup last summer. In winning their group, they sent Italy and England home before the knock out stage. Then they beat Greece to advance to the Round of 16.

Costa Rica relies on its defense, which is ranked 10th in the world over the last 4 seasons. They face a road game against Canada in Toronto in the group stage, but they should win their group before most likely playing the United States in the semi-final.

List of win probabilities for the 2015 Gold Cup

1. United States, 39.1%.
2. Mexico, 33.6%.
3. Costa Rica, 11.7%.
4. Panama, 4.7%.
5. Honduras, 4.7%.
6. Jamaica, 2.3%.
7. Guatemala, 1.8%.
8. Canada, 1.4%.
9. El Salvador, 0.9%.
10. Trinidad and Tobago, 0.7%.
11. Haiti, 0.1%.
12. Cuba, 0.1%.

Television Interview on Ronan Farrow Daily

By Dr. Ed Feng 1 Comment

Ronan Farrow interviewed me and Maurice Edu about the World Cup on his MSNBC show yesterday.

I was pumped to meet both the host and one of the best soccer players in the United States. However, there’s not much contact when they film you from a remote location.

To do the interview, I went to a studio in my home town of Ann Arbor. A nice guy Tony set everything up.

From a remote location, I could only hear Ronan and Maurice in my earpiece. I couldn’t see them or what appeared on television.

Still, it was fun. We talked World Cup, the United States’ chances against Belgium in the Round of 16 and how numbers affect the psychology of players.

To view the interview, click here. If you’re viewing on Tuesday, July 1, it should be the main video under “Betting on the World Cup.” Otherwise, you might have to scroll through the videos on the right.

Ensemble win probabilities for the World Cup after the group stage

By Dr. Ed Feng Leave a Comment

The wisdom of crowds.

In making predictions, it’s best to include the predictions of many different methods. Each method has its strengths and weaknesses, and taking an average gives better results.

The Power Rank began when I developed an algorithm for ranking teams. However, as I learn more about making predictions, my method will take its place along with others in an ensemble of predictors.

Ultimately, I think this will be most useful in predicting the NCAA tournament. But right now, I’m practicing on the World Cup.

My recent article on bettingexpert looks at the ensemble predictions for the World Cup after the group stage. To check it out, click here.

New international football / soccer rankings show recent form of nations

By Dr. Ed Feng 1 Comment

The FIFA rankings suck. Not only do they poorly predict the outcome of matches, but you have to wait a month for updates.

The Power Rank international football / soccer rankings do better. The ranking algorithm considers margin of victory in adjusting for schedule strength in international soccer. As an academic study has shown, using margin of victory is critical in making predictions.

In addition, the international rankings are now updated daily.

This constant updating is interesting during the World Cup. My rankings use a 4 year window of matches and weight matches by their importance.

World Cup Finals: 4.
World Cup Qualifiers, Confederations Cup, Continental Finals: 3.
Continental Qualifiers, 2.
Friendlies, 1.

Since we’re in the middle of a World Cup, the rankings add important matches each day while dropping results from the previous World Cup. This leads to some interesting changes for certain teams.

Spain and the Netherlands

The Netherlands dominated Spain in a 5-1 win last week. This dropped an aging Spain team down to 6th. The FIFA rankings still have Spain as the top team.

The Dutch have risen to 4th. It mystifies me why more people didn’t think this traditional power could win this World Cup.

Germany and Brazil

While most other respectable rankings have Brazil on top, the weighting of matches in The Power Rank vaults Germany ahead of Brazil.

Germany has played well in the last two World Cups. In 2010, they dominated Argentina in a 4-0 rout. Just last week, they beat Portugal, another top 10 team, by the same margin.

With no weighting, Brazil would be the top team in The Power Rank.

United States and Ghana

The Yanks are 18th currently, one spot above the Ghana squad they just beat.

The United States won the game because of two great finishes by Clint Dempsey and John Brooks. However, between these two goals, Ghana dominated possession and scoring opportunities. They were the better team.

Colombia and Chile

These two South American teams are in the top 10. Colombia is ranked higher at 5th, but Chile is not far behind at 7th.

From this World Cup, the Colombia looks like the better team. They continue to score goals despite the absence of Radamel Falcao, their leading scorer in qualifying.

Moreover, my aggregated win probabilities before the World Cup gave Colombia an almost 4% chance to win it all. Chile only had a 1.9% chance.

Belgium and France

Belgium has generated much chatter as a dark horse World Cup champion. Young players like Eden Hazard have dazzled on the pitch at this World Cup.

However, their performance over the last 4 years ranks them 13th in The Power Rank. That puts them lower than France (9th), a team no has talked about as World Cup champion. (Of course, France is missing star winger Frank Ribery for this World Cup.)

Belgium’s play as a team does not make me believe they will contend for the World Cup title. My aggregated win probabilities before the tourney agree with this assessment. Belgium had the 11th highest win probability at 2.3%.

Rankings of World Cup teams

Here are rankings of the 32 World Cup teams that consider matches from June 20, 2010 through June 19, 2014. The record gives wins, losses and ties over the past 4 years. The rating gives an expected margin of victory against an average international team.

1. Germany, (37-7-11), 2.52
2. Brazil, (40-9-12), 2.28
3. Argentina, (32-8-15), 2.15
4. Netherlands, (33-9-11), 2.09
5. Colombia, (24-8-11), 2.09
6. Spain, (45-8-8), 2.05
7. Chile, (29-17-9), 1.69
8. Uruguay, (28-14-15), 1.69
9. France, (28-11-12), 1.59
10. Portugal, (26-9-13), 1.54
11. Ecuador, (17-14-15), 1.48
12. Mexico, (35-18-17), 1.48
13. Belgium, (22-8-12), 1.44
14. England, (25-8-14), 1.43
15. Ivory Coast, (31-7-9), 1.42
16. Italy, (22-12-21), 1.40
17. Ghana, (30-15-14), 1.29
18. United States, (37-17-12), 1.25
19. Russia, (24-6-13), 1.25
21. Switzerland, (20-7-12), 1.23
23. Croatia, (24-10-11), 1.16
24. Nigeria, (29-11-21), 1.11
27. Japan, (33-12-13), 1.07
28. Bosnia-Herzegovina, (21-14-7), 1.03
30. Costa Rica, (25-23-19), 0.95
32. Greece, (24-8-16), 0.91
34. Australia, (26-16-11), 0.87
35. Iran, (30-8-16), 0.85
38. South Korea, (24-17-12), 0.80
43. Honduras, (22-24-18), 0.75
50. Cameroon, (16-13-12), 0.60
53. Algeria, (19-10-6), 0.56

For all teams, click here.

Predictions

The Power Rank also provides predictions for each match and stages of the competition, both of which are update nightly.

These predictions use a different set of rankings that consider a 12 year window of games. Research as shown that these calculations are as accurate in predicting match outcomes as using a 4 year window.