How Proactive is Your Favorite MLS Team? / by Jared Young

By Jared Young (@JaredEYoung)

Jonathan Wilson, most notably the author of the soccer epic Inverting the Pyramid, wrote a piece  in 2012 for the Guardian called “The question: Position or Possession?”. In it, he discusses the merits of both possession and position and supposes that it’s difficult if not impossible to control both possession and position simultaneously. He cites Barcelona and their tiki-taka philosophy as a team that aspires to extreme levels of possession, while Chelsea prefers to maintain position on the pitch defensively in order to take advantage of space behind the offense.
The post got me thinking about how to measure whether or not a team was proactive in their use of the ball or reactive. I’m not convinced those are the correct terms to describe the two strategies, but I’m not sure there are two terms that define the extreme type of play adequately, primarily because I think the words mix two dimensions. The chart below illustrates the two dimensions on which a team builds its strategy.

StrategicChoices.png

The first is a passing dimension. On the one extreme, there is a direct passing philosophy which looks to push the ball up quickly to take advantage of space once a team gains possession. At the other end is an indirect passing philosophy which involves short passes that build possession up the field and eventually attempt break down the defense.

The other dimension is where a team begins their initial line of resistance; the pressing dimension. There are teams that give high pressure up the pitch hoping to get a turnover closer to the goal (e.g. Barcelona). There are also teams that allow opponents deeper in order to maintain defensive formation and positioning longer, and thus use a low pressure technique (e.g. Chelsea).

Teams tend to pair two ends of each dimension, so that there are two notable styles of play. Teams that press high also tend to pass more indirectly. This is mostly due to the physical demands of the high press. Teams cannot afford to take risky passes after working so hard to gain possession. Similarly, teams that sit back and offer low pressure tend to pass the ball more directly. Of course, as Wilson mentions, the best teams are able to do all of the above, and they can play any way needed based on the score of the game and what the opposition is doing.

StrategicChoices2

To measure a team’s level of proactivity or reactivity we need to understand what statistics characterize games at the extremes. I located every MLS game in 2014 where one team held 65% or more of the possession. The thinking there is those are matches where one team is looking to cede possession and one team is looking to control possession. These possession levels are not necessarily due to dominant performances, but rather games where extreme tactics are carried out.
I deleted games that were decided by 2+ goals or more. The rationale there is game state can dramatically shift a team’s strategic intent during the course of the game. Closer games are more likely to have teams consistently employ their original strategic intent.

There were 16 such games played in MLS in 2014. Here is a breakdown the statistical results of the games. The team with higher possession is considered the proactive team and the team with lower possession is the reactive team. The average possession for the proactive teams is 68%.
Here are shooting results between the two styles of play.

Style Shots Per Game Finishing Rate (%) Shots on Target (%)
Proactive 16.8 4.9 29.9
Reactive 9.2 12.2 44.9

Proactive teams shoot twice as often as reactive teams,  but they get fewer of those shots on target and score less frequently. This is because reactive teams are keeping their defensive shape and pressuring much closer to their goal, making it more difficult for the opponent's offense to get shots to the target or convert them.

There are similar differences in regards to passing.

Style Passes % of passes in final 3rd

that were crosses

% Long Passes (25+ yds) Pass Completion %
Proactive 530 18% 13% 83%
Reactive 259 13% 21% 68%

Extremely proactive teams average 530 passes per match, while extremely reactive teams average 259. The ratio of passes in the final third also holds up consistently, 152 to 86. However, the types of passes made by each team has some notable differences.

Proactive teams use 5% more of their passes in the final third on crosses. If defenses are truly keeping their compact shape, then offenses generally work the ball out wide to the available space.  More crosses make sense. Reactive teams strike 8% more of their passes 25 yards or longer (for our purposes, 25+ yard passes are called “long passes”). This is an indication of direct play. The longer passes leads to a lower completion rate. Don’t be fooled by the lower overall pass completion rate of reactive teams; the completion rate difference is due to risk-taking when they have possession. More direct passing comes with more risk as the passes are longer and are generally to players who are on the move. Proactive teams complete 15% more passes than their reactive counterparts.

While this analysis certainly isn't comprehensive or perfect, I do believe it allows accurate insight into how teams would operate at the extreme ends of the strategic spectrum.

Proactive Score

The goal is to develop a simple score that shows fans and analysts where on the spectrum a given team plays. To do that, I started with the variables that had the most spread in the analysis above. I didn't look at shooting statistics, as those measure an outcome of the style of play, not the style of play itself. The two strongest differences were total number of passes and long pass percentage. Of minor comfort is that a multivariate regression including total passes attempted, long passes attempted, and a home/away flag were all statistically significant in predicting possession of MLS teams at the game level with an Rsquared value of 70%.

That said, using passes to identify large spreads in possession is nothing short of obvious. But without Opta data, there are limited choices for fans to use to determine a team’s strategic intent.
After trying a combination of descriptive metrics and looking at the corresponding spread of results, I landed on using total passes attempted and two times long passes to create a score. While multiplying long passes times two adds complication to the formula, the larger spread does create more separation in the target metrics.

From there I scored a team’s performance on a scale of 1 to 7, with 7 being an extremely proactive team. The result when looking at the games in 2014 is a reasonably normal bell shaped curve.

The metrics that result from the modeled Proactive Score don't have as much spread as the small sample of 16 games at the extremes, but the model rank orders in line with the sample. In short, It isn't distributed as perfectly as our smaller sample size, but the trends remain

Pscore SOG/Shots Home Possession Pass Completion % Finishing % Opp. Finishing %
7 35% 63% 85% 11% 13%
6 37% 59% 84% 10% 12%
5 36% 57% 81% 11% 11%
4 34% 51% 80% 11% 11%
3 40% 48% 78% 14% 11%
2 39% 46% 74% 12% 7%
1 43% 39% 69% 15% 10%

Proactive teams have more trouble finding the target due to the reactive team's defensive positioning and density around the goal. Reactive teams get more shots on target because they are taking their shots with more open space between the shooter and the goal, and are more likely to be on a breakaway. Shooting percentage for all teams is correlated with the shooting percentages in our smaller sample of the 16 lopsided possession games, though proactive teams shoot much better than the initial sample indicated. This could be because I chose to only look at close games which may indicate unlucky shooting by the proactive teams.

So what can this Proactive Score tell us about the 2014 MLS season? Here is a table of each team and their score on both the road and at home. Playoff teams are in color – orange if they were proactive, red if they were reactive.

TeamTotal PscoreAway PscoreAway PPGHome PscoreHome PPG
LA Galaxy 4.9 4.3 1.2 5.6 2.3
Columbus 4.7 4.5 1.2 4.9 1.8
Seattle 4.7 4.3 1.6 5.2 2.2
Real Salt Lake 4.6 4.4 1.1 4.8 2.2
New York 4.4 4.1 0.9 4.6 2.0
Sporting KC 3.9 3.3 1.6 4.5 1.4
Vancouver 3.8 3.2 1.1 4.4 1.9
Portland 3.8 3.4 1.6 4.1 1.4
Houston 3.7 3.5 0.6 3.8 1.6
Colorado 3.6 3.6 0.5 3.5 1.4
San Jose 3.5 3.1 0.4 3.9 1.2
Toronto FC 3.5 3.4 1.1 3.6 1.4
Philadelphia 3.5 3.3 0.8 3.8 1.5
D.C. United 3.4 3.0 1.3 3.8 2.1
Montreal 3.3 3.0 0.3 3.6 1.3
FC Dallas 2.9 2.7 1.0 3.1 2.3
New England 2.8 2.3 1.3 3.4 1.9
Chicago 2.8 2.5 0.8 3.1 1.4
Chivas USA 2.7 2.1 0.8 3.3 1.3

A couple of things jump out. The first is that the seven most proactive teams all made the playoffs. Then there is a fairly noticeable gap before more playoff teams are found.  Only three reactive teams made the playoffs; the New England Revolution, FC Dallas and D.C. United.

Next, we can test the theory that the reactive teams were indeed reactive. A plot of shots taken by finishing rate will indicate if the reactive teams took less shots but finished at a higher level. The orange dots indicate proactive teams that made the playoffs. The red dots indicate the three reactive teams. Blue dots represent non-playoff teams.

FinishingRatesByShotsAttempted

Both FC Dallas and D.C. United show the shooting results of a reactive team. They ranked 17th and 18th in the league in shots taken but were 1st and 2nd in the league in finishing rate. Unlike the other two reactive teams, New England is in the middle of the pack from a shooting perspective. This is peculiar given the Revolution were the most reactive team that made the playoffs. More work would need to be done to understand the secret to the Revolution’s success from a number’s perspective. They attempted fewer passes with a higher percentage of long passes than other playoff teams, but were able to attempt an above average number of shots and finish them at an average rate. They were also slightly better than average defensively.

According to Jonathan Wilson, reactive teams prefer position to possession with a primary goal of keeping defensive position. The three reactive teams that made the playoffs were all ranked in the top eight in the league in fewest goals allowed, with D.C. United tying the L.A Galaxy for best in MLS.
Measuring a team’s tactical intent has a long way to go, and this is a very humble initial look. More detailed Opta data would allow for much deeper understanding of a team’s choice between possession and position. The importance of putting a measurable number to these tactics is so other statistics can be understood relative to that context. If we can understand what makes one reactive team successful while another fails, we can better understand the effectiveness of home and away strategies, in-game adjustments, and why (or why not) teams are successful.