RSSeNEWS to be determined...

With upsets for France and Spain in the first round of group matches in World Cup 2010, pundits are revisiting their predictions. But as the data accumulates, some statisticians question how long the underdogs can maintain their success.

On BBC Radio 4's Today programme Stefan Szymanski commented "we've had a number of upsets; look at Fifa rankings and see how many games went with the rankings; six draws, nine with rankings, five against - just over a third ... pretty much what you'd expect - the underdogs producing a few upsets. The problem for the underdogs is that as the competition wears on it becomes less and less probable that they can sustain that kind of performance."

"Just look at the history of past winners, when only six or seven teams have been in that group ... when are other teams going to break through?" he asked. Szymanski noted "the potential for countries like USA and China", saying "people have talked about this for many years but still it doesn't seem to be happening." He explained that "the talent is very concentrated in a small number of countries".

Jim O'Neill, Head of Global Economic Research for Goldman Sachs, said that other than the Spanish result, the results were "reasonably predictable so far". O'Neill, who is renowned for his predictive powers and heads the Red Knights, a consortium with ambitions to buy Manchester United, saw similarities in the World Cup contest with events in the financial markets, in particular the poor performance of 'Club Med' countries - Greece, Spain and Italy.

Using the results of the tournament's first round, FiveThirtyEight.com has recompiled its odds. Since 16 June, Argentina has moved ahead of Brazil and the  Netherlands and is now rated as the team with the best chance of reaching the final. Its neighbour Uruguay has overtaken England and is now ranked fourth.

The results are derived from about 10,000 simulations based upon ESPN's SPI (Soccer Power Index). The SPI rates the percentage of points a team would accumulate in a tournament amongst all the teams in the world in which each met all other contestants in turn.

FiveThirtyEight's Nate Silver has made a comparison of the odds generated by the SPI against those offered by the consensus odds shown at the www.oddsportal.com, which monitors betting site odds. He finds some "significant - and systematic – discrepancies" and comments that "the bookmakers' odds seem to be too slow to catch up to the matches that have been played so far".

Silver acknowledges that the SPI may be wrong but asserts: "the biases seem systemic enough – toward Europe and against the rest of the world; toward wealthier, more populous nations and against their opposites; toward pre-tournament expectations and against the predicament that the teams actually find themselves in – that there are probably some significant inefficiencies in the prices the bookmakers have established."

Taking a forensic approach, the Guardian datablog has sourced World Cup data from Opta to enable comparisons between 2010 and previous tournaments. Opta analyses "every shot, every tackle and every goal" and has made available its complete statistical analysis of all the games in the tournament up to 17 June.