MLS Head Coaching Bias Part 2: Playing Experience

At the end of my post on MLS coaches lacking experience, I mentioned that I also was going to follow up with a look at if MLS teams also prefer head coaches with playing experience. Here is a table comparing the top two leagues in the world, La Liga and the EPL with MLS

League	Percent of head coaches w/ playing experience	Fraction
MLS	95%	18/19
EPL	100%	20/20
La Liga	85%	17/20

Interestingly, all leagues overlook managers with no playing experience. The only manager who has no managing or playing experience, Fran Escribia of Elche, led them to the first division after a 25 year absence. The only MLS head coach with no professional playing experience is Sigi Schmid - who has the most wins in the history of MLS. MLS and teams all around the world should stop having this prejudice while looking for a new head coach and reap the rewards.

MLS Head Coaching Bias Part 1: Coaching Experience

Recently, I noticed a trend of MLS coaches being hired for their first professional head coaching gig. although guys like Caleb Porter offer a new perspective on building a team, I thought it may not be the best idea. So, I took a look and compared the percentage of first-time MLS Head Coaches and the percentages of the top two leagues in the world. I didn't include college and youth national team coaching as 'experience'(sorry Caleb Porter and John Hackworth), but decided to put Francisco Javier Rodríguez Vilchez of Almeria in the head coaching experience group due to the fact that he coached Almeria's B team, which plays in the Spanish third division

League	Percent of first time head coaches	Fraction
MLS	68%	13/19
EPL	15%	3/20
La Liga	10%	2/20

Even more frightening, there is only one MLS head coach to have started outside MLS. Even though coaches like Aron Winter and Ruud Gullit have failed in MLS, experienced managers tend to preform better due to the 10,000 hour rule mentioned in Malcolm Gladwell's book Outliers. Teams should also stop hiring just managers with playing experience. When Carlo Ancelotti was asked about the subject of playing experience, he commented, "I don't see the connection. My dentist is the best in the world, but he's never had a particularly bad toothache." I'll take look at that in a future post.

Which wins championships, offense or defense

Bear Bryant once famously proclaimed, "Offense sells tickets, but defense wins championships." Football statisticians have proved that wrong so I decided to check if that is true in soccer too. So I took a look back at MLS Cups and conference finals going back to 2002 and looked at the team's goals for and goals against to determine which team is better offensively and which team is better defensively. The results are below.

Better Offense, Better Defense	Better Offense, Worse Defense	Worse Offense, Better Defense	Worse Offense, Worse Defense
11	12	10	3

The takeaway here is that it doesn't matter in the battle between offense and defense. A trend I noticed was thyat generally, in the first few MLS Cups, more defensive teams won. In 2003, only better defensive, worse offensive teams won. In comparison, 2012 was only better offensive, worse defensive teams.

Does possession matter?

Last month when Michael Bradley commented that possession is overrated, it rekindled an age old debate whether more possession leads to more wins. The MLSsoccer.com article took the opposing side, citing a graph showing the percentage of teams with more than 50 percent of the possession who made the playoffs. Around the same time, the MLSsoccer.com also published an article that San Jose Earthquakes, the winner of Supporter’s shield in 2012 was the best attacking team in the MLS history. When checking their stats, I noticed that they managed to win many times despite having less possession. I digged deeper - and San Jose Earthquakes are not alone, so did New York Red Bulls on their way to winning Supporter Shield in 2013 - in fact they had a very convincing win over Dynamo (3-0) with as little as 39% possession. I picked up few more games at random, and sure enough there were plenty of examples in MLS last season where side with lower possession won.

At this point, I decided to investigate further, collecting more data points systematically. I picked up three rounds (2, 18 and 32) in the beginning, middle and end of the season and looked at all the games that produced a result.What I found was that there is some positive correlation between more possession and winning, unfortunately the correlation is not very strong, as shown below(I didn't include ties):

More Possession	Equal Possession(49-51%)	Less Possession
13 wins	7 wins	12 wins

So, I would rather agree with Michael Bradley, possession is indeed over rated. It is a factor but not an overwhelming one, at least in MLS. In search of other factors,  I looked at few other statistics like total shots, shots on goal, duals won etc. So far I have not been able to find any single overwhelming factor but found that shots on target has higher correlation with win than possession. I took the same games from last year and compared the winning and losing team's shots on goal data.

More Shots on Goal	Equal Shots on Goal	Less Shots on Goal
17 wins	8 wins	7 wins

As a side note, I observed that only three teams in 32 games managed to win in spite of having less possession and also with fewer shots on goal. For one of them, possession was almost equal (47% vs 53%) and difference of shots on goal was just 1;  in another instance, the winning team’s goalkeeper was MOTM, and in the third case the winning side had two stoppage time goals. I'll be sure to revisit this topic in a future post with more factors and data and hope to pinpoint three things which a team must focus on in order to win.
*Here is a link to the data which I have collected