Even without the help of modern soccer technology, soccer coaches – especially in my experience growing up in the American soccer system – had a passing interest in statistics. On multiple occasions, while sidelined with an injury, I was stuck tallying how many times my team won and lost "50/50" balls as well as the "second balls" that immediately followed.
My first observation was just how difficult it was to collect this information in real time. My second observation was just how much these measurements varied depending on who was collecting the stats. Luckily, with Opta's analysts and event definitions, we can get a much stronger grasp on these statistics which have such a bias in the trenches of youth soccer.
During the 2012 MLS season, there were 5772 aerial 50/50 duels that were directly followed by an attempted pass – that's nearly 18 per game. Each duel is won by the player that reached the ball first, but that doesn't necessarily mean that the duel winner's team immediately regained possession of the ball; or rather, the second ball.
The team that wins an aerial duel gains possession of the ball directly afterwards 91.9 percent of the time. This is a smidgen higher than the Barclays Premier League in 2012 – where the overall retention rate was 89.9 percent. And, as expected, some MLS teams are better than others at this.
This is the aerial victory retention rates for MLS in 2012:
|Real Salt Lake||0.9517||138||145|
|New England Revolution||0.9387||245||261|
|Seattle Sounders FC||0.9381||273||291|
|San Jose Earthquakes||0.9271||229||247|
|Sporting Kansas City||0.9196||263||286|
|New York Red Bulls||0.9087||189||208|
Montreal were particularly effective last year, only conceding possession on eight of their 206 aerial victories. On the other hand, the MLS Cup champion LA Galaxy struggled badly in second-ball retention, failing to secure possession in more than 14 percent of their aerial victories.
While retaining your own aerial victories is important, it's also quite useful to pickpocket the victories of your opponents.
Here is the aerial loss retention rates for MLS in 2012:
|Seattle Sounders FC||0.0945||26||275|
|Sporting Kansas City||0.0936||35||374|
|New England Revolution||0.0773||16||207|
|New York Red Bulls||0.0752||20||266|
|San Jose Earthquakes||0.0745||21||282|
|Real Salt Lake||0.0506||8||158|
Columbus led the way, stealing possession of an impressive 10.1 percent of their team's 257 aerial losses. LA again struggled, nabbing possession on only 5.7 percent of aerials won by their opponents and was only undercut by Salt Lake's 5.1 percent
While these statistics are interesting – and likely an outgrowth of the particular playing styles of specific teams – the lack of correlation between retention rates and team standings is fascinating. The Galaxy struggled on both of these metrics – but clearly managed to win plenty of games. Maybe youth coaches should start picking new contrived statistics to tally?