Do we overestimate the impact of recent form?

Form is one of the most frequently discussed concepts in football. Players, coaches, journalists and pundits routinely refer to the momentum generated by a succession of victories. Form guides are ubiquitous in pre-match reviews, the idea being that recent results are indicative of a team's chances of winning their next match. But is this idea founded in fact?

Looking for the impact of form, or momentum, in football is tough. There are a multitude of confounding variables, most notably variations in the quality of opponents, the effects of home advantage, changing team selections and small sample sizes. Situations are not replicable, making it difficult to study whether win probability has been enhanced by a recent run of victories. Nevertheless, there are some simple statistical tests that we perform to try to detect whether form has any impact on outcome of subsequent matches.

One test is to look at the frequency with which winning streaks occur. Streaks are a natural feature o…

Best Feet Forward: a willingness to wield the weaker foot

In first half stoppage time of a Serie A match last November, Bologna's Simone Verdi curled a free-kick with his right foot over the Crotone wall and past the two-handed dive of Alex Cordaz. Earlier in the half, Verdi had hammered a left-footed free-kick into the top corner of the Crotone goal. This may well be a unique achievement in the big European leagues: Verdi is the only player on record to have scored free-kicks with both feet in a single match. He appears to be right-footed (at least, he takes penalties with his right foot); yet, over the last four seasons, he has taken more shots with his left.

Genuinely two-footed players are a rare commodity (and appear to be paid accordingly). A study of 'footedness' during the 1998 World Cup found that less than a quarter of shots by right-footed players were taken with their left foot, and less than one in six by left-footed players were taken with their right. Only a tiny proportion of players appeared to be equally comfor…

Exceeding Expected Goals

From blogs to the BBC, the concept of expected goals (or xG) has entered the mainstream media's lexicon. It has caught on because it's a useful concept; it's a useful concept because football is a low-scoring game. Chance (or luck) can be the difference between victory and defeat, a good day or an off-day. Expected goals, however, measures what would have happened on an average day.
It's a simple quantity to measure. Shots are assigned a number between the 0 or 1: the proportion of similar shots (from the same position, for example) that have resulted in a goal. This number, sometimes referred to as chance quality, is then added up over every shot taken by a team during a match (or a season) to calculate the number of goals that you would have 'expected' them to score.
Conventional xG models do not take into account the identity of the player taking the shot. You need a dataset comprising many thousands of shots to properly measure chance quality over all posi…

Liverpool move faster than most in the market.

While Liverpool were the biggest spenders of the transfer window -- they were the only EPL club with a net spend in excess of £100m -- another striking feature of their summer business was the speed and decisiveness with which they got it done: all four of their major signings were completed nearly three weeks before the end of the transfer window.

Prompt and decisive is a good description of Liverpool's recruitment strategy in the second half of the John Henry era. Since 2015, Liverpool have purchased 15 players in the summer transfer window (excluding free transfers, or those for which the fee was undisclosed) for a grand total of around £400m. Only one of those players was bought in August and that was the somewhat opportunistic purchase of Alex Oxlade-Chamberlain. The majority of their new recruits in recent years have had at least a couple of weeks to bed in before the season started.

How do Liverpool compare with the rest of the EPL in terms of the speed of their transfer …

Inward-looking England invest in the future.

In the 65th minute of England's friendly against Costa Rica last week, Nick Pope stepped onto the pitch to make his first international appearance for England. At the same moment, Trent Alexander-Arnold's senior international debut came to end. Both players were selected for England's World Cup squad without having ever played for the senior men's side; only 9 other players at this World Cup have achieved that particular feat.

It is no secret that Southgate has selected a youthful side to take to Russia, but how do they compare in terms of age and experience to the other 31 tournament participants?

Figure 1 plots the average age of each World Cup squad against the average number of senior international appearances the players had made when the final squads were announced. As you might expect, there is a clear relationship between age and number of appearances. The average World Cup player is nearly 28 years old and has made about 34 appearances for his country.

Costa …

What can we expect from the 21st FIFA World Cup?

On Thursday 14th June, at 6pm local time, the 21st World Cup will kick off in Moscow; the first to be held in Russia, and only the second in Asia. Thirty-one days later, two of the thirty-two participants will contest the final.

There are sure to be shocks and surprises along the way, but what should we expect from the tournament before the first ball has been kicked? Who are the favourites? How likely are we to have a European, South American, Asian or African winner (or perhaps a first-time winner)? Which is the toughest group, or the easiest? How far is each side likely to get?

Based on a simple model for predicting match results, I've simulated the World Cup 10,000 times to evaluate the likelihood of various outcomes and investigate some of the quirks of the tournament. If you're interested in the technical details, scroll down to the Appendix. As the tournament plays out, I'll be rerunning and updating my predictions: follow me on Twitter (@EightyFivePoint) if you…

Show me the Money: how much is each premier league position worth?

With less than a quarter of the season remaining, most EPL clubs will finish within a couple of places of their current league position. For some clubs this could mean the difference between survival or sinking into the Championship; for others, swimming with the big fish in the Champions League or the smaller shoals of the Europa League. For the rest the consequences are less dramatic.

While fans chew at their finger nails, club owners and directors will be busy assessing the financial consequences of each permutation as they plan for next season. A significant proportion of each club's revenue next year will depend on their final league position in May. The difference between 8th and 10th may not seem particularly important, but how much are these few extra places worth in terms of the cash prizes on offer? More generally, what is the total amount a club can expect to bank as a direct consequence of their final league position?

The Prizes on Offer
The financial rewards associat…