The Utility of Crossing in Soccer
Over the past ten or so years, the emphasis on crossing in soccer has been on the decline. Teams have moved toward tactics, such as tiki taka, that stress shorter passes.
However, there is some evidence that crossing may be making a comeback. Before the English Premier League season was stopped due to the coronavirus, Liverpool was on top of the League and on record-setting pace. Liverpool had sent in the second highest number of crosses in the League, and was on pace to reach 884 crosses by the end of the season. Liverpool deployed its fullbacks, Trent Alexander-Arnold and Andy Robertson, high up the pitch, allowing them to attack frequently, and cross the ball often. Manchester City, the club second in the table when the season was stopped, had the highest number of crosses in the League, and was on pace to reach 979 crosses by the end of the season. To put those numbers in perspective, during the prior season, 2018-2019, Everton, which finished eighth that season, led the League in crossing with just 817 crosses. The season before that, Tottenham led the League with 831 crosses.
In 2014, Jan Vecer, a math professor at the Charles University in Prague, disseminated research through which he argued that crossing actually had a negative impact on a team’s goalscoring. Others, however, have disputed that conclusion.
I analyzed Major League Soccer statistics from the 2018 and 2019 seasons to gain further insight into the impact of crossing on team success.
My data was scraped using Selenium from https://www.fbref.com/.
Here is the data in table form:
The data for crosses was right skewed. I defined an outlier as any point at least two standard deviations away from the mean. There were two outliers for crosses: the Portland Timbers in 2019 and the LA Galaxy in 2019.
The data for points gained was normally distributed.
No Significant Correlation Between Crossing and Points Gained
Examining the entire dataset, there was almost no correlation between the number of crosses and the number of points gained (r = .07), as shown below:
Removing the two outliers made little difference (r = .05).
Also No Significant Correlation Between Crossing and Goals Scored
Similarly, there was almost no correlation between crosses and goals scored, regardless of whether or not the outliers were removed (r = .08 with the full dataset, as shown below; r = .07 with outliers removed).
Moderate Correlation Between Completed Crosses and Points
There was, however, a correlation between the number of crosses that a team completed and the number of points that the team gained (r = .23 with the full dataset; r = .26 with outliers removed, as shown below).
The correlation between completed crosses and points indicates that effective crosses may have some impact on team success. In other words, "good" crosses may still have a place in modern soccer.
Completed Cross Rate
The most substantial correlation in the dataset was between a team's completed cross rate and points gained (r = .29 with the full dataset; r = .30 with outliers removed). However, this correlation probably does not tell us much about crossing specifically. Indeed, it makes sense that teams that have more skill will tend to have a higher rate of completed crosses and also gain more points.
Simply putting in a high volume of crosses may not do much to help a team win, but completed crosses are correlated with measures of team success such as points gained and goals scored. So while crossing may be past its prime, it's not going away any time soon.