Sunday, 24 June 2012

May the best team win? Chances are they will not


In an attempt to understand and come to terms with the early exit of the Dutch football team from the European Championships I started to review the team’s performance during the qualification phase. They must have been a poor team in that phase as well. But I found an amazing track record. The Dutch team scored 37 goals in ten matches, which was the highest of the 53 teams in the competition. Ranking all the teams of the qualification phase the Dutch came in second with 27 points, just after Germany who totalled 30 points. During the qualification phase we only lost one game, at that time we already had qualified for the finals. How come such a great team, with top players like Wesley “The Sniper” Sneijder and Klaas Jan “The Hunter” Huntelaar, didn’t make it to the finals?  They didn’t even manage to score a single point in the group phase.  I found the answer in basic probability analysis.

The European Football Championship starts with a pool phase of 4 groups. In each group 4 countries play against each other to determine first and second in the group. After the group phase the knock out phase starts with quarter finals, semi-finals and finals for the 8 remaining teams. The Netherlands was up against Denmark, Germany and Portugal. Given the tough competition, this group was called the group of death. Trying to figure out what the probability of surviving the group phase was I started with some basic calculations. To estimate the probability of winning, losing or a draw when playing against these countries I looked at their ranking in the UEFA list . Germany and the Netherlands score about the same (40860 for the Netherlands, 40446 for Germany) Based on this score I thought it reasonable that the probability of a draw when playing against Germany would be about 50%. I set the probability of winning or losing from Germany at 25% each. Denmark and Portugal both had a much lower score than Germany and the Netherlands in the UEFA list. A reasonable probability of wining from the Danish and Portuguese team would be 40%, losing the game at 30% with the same probability for a draw. Note that the probability of winning all the games in the pool phase for the Dutch team than becomes 40%*40%*25%, or only 4%. Based on these assumptions the probability the Dutch would survive the pool phase (for simplicity reasons, scoring at least 6 points) is 28%.  Thus surviving the pool phase for the best team (The Netherlands has the highest UEFA ranking of all countries in the group) is slightly better than one in four; this is similar to drawing a random name from a set of four. It’s a lottery.

Assuming the Dutch team would have managed to get to the knock out phase, the teams they would have been up against would be the strongest in the competition. The probability of winning a game would have been similar to the flip of a coin. Thus the probability of making it to the finals would have been 28%*50%*50%=7%, winning the championship even worse, only 3.5%.  Thus, although the Dutch were one of the favourites, qualifying as second for the final round of the European Championship, it was tough luck that led to their early exit. As basic probability analysis shows, the probability of the best team not winning the championship is high; winning the championship is more like wining a lottery. This insight helps to sooth the pain a little and not only supports me, but any country that didn’t make it to the finals. 
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