Turf and Injuries: The Data Hurts by DMP

One of the most peculiar matches of the 2018 regular season occurred on August 18th. The LA Galaxy were already stretched thin from injuries to both dos Santos-es and Romain Alessandrini (their three DPs) and defender Michael Ciani for Sigi Schmid’s return to Seattle. But when they showed up in town, there was a huge name - perhaps the biggest name in MLS - missing from the lineup. That name was Zlatan, and by all indication his absence was voluntary.

By the end of the afternoon, the Galaxy really could have used one of the greatest players ever to kick a soccer ball. They ended up suffering their worst loss of the season and Seattle notched their best (5-0). Oh yeah, and the Galaxy missed the playoffs by less than three points.

We all know why he missed that game. It’s because the Sounders play on FieldTurf. There’s a perception out there that playing on artificial grass increases the risk of injury, and Zlatan had hurt his knee not long before (not on turf).

The superstar is not alone in his perception. I remember being disappointed not to see Thierry Henry play at CenturyLink Field in 2013. In fact, a group of Canadian researchers surveyed 99 MLS players back in 2011 and found that the vast majority (93%) said they believe third-generation artificial turf (FieldTurf) increases the risk of injury.

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Ranking MLS' Best Foreign Goalkeepers by Bill Reno

It’s hard not to have a love-hate relationship with the MLS offseason. On one hand, we get to talk about goalkeepers more often. (A massive plus for anyone.) Typically the narrative wraps up a year-long performance in one or two sentences - “Goalkeeper X will look to build off of last year’s success by relying on his shot stopping and distribution skills.” - but that’s hardly a problem considering the larger headache that resurfaces this time of year. Every January we hear about an unnamed MLS team being linked to a foreign goalkeeper. We just had one happen last week, with a “lucrative offer” apparently on the table for a German goalkeeper.

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Player Value Recap 2018: Refining a System for Ranking MLS Players by Dave Laidig

Creating an all-encompassing player value metric is an ongoing process, with more data adding more insight and texture to its meaning. But the challenges are worthwhile. The ability to compare players from different positions on equal footing, like PER for the NBA or WAR for MLB, allows one to test assumptions for what makes a team successful, how players fit together, and where resources might best be spent. If you haven’t already, read my pieces from last year (here are parts one and two). But this is an update on my progress to creating a metric to describe how game actions affect game outcomes, based on the context of team possessions.

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Why the new MLS Playoff format doesn't create a more meaningful regular season by Jared Young

Major League Soccer has updated their playoff format for 2019 to a March Madness style single elimination tournament that will take roughly a month play out. The prior competition used a combination of single elimination and home and away ties over a month and a half period, and had long breaks in the action. The one clear benefit of this change is the shortened duration of the tournament. Avoiding the November international window will create a compact and uninterrupted tournament that should improve the momentum of the story lines that emerge.

The new format is also supposed to benefit the higher seeds, as the single elimination games will give advantage to the home teams, versus the old method of home and away legs for each team. This seemingly makes regular season games more important. More Victory! [Insert scratching record sound here]. These types of simplifying statements make my geek antenna start to hone in on theoretical galaxies of mathematics. Sadly, the only off switch I have for my antenna is my keypad and a Google docs session. So let’s dig in and deconstruct this new tournament bracket and see who benefits and who does not.

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Our Favorite ASA Articles of 2018 by Drew Olsen

During a recent American Soccer Analysis shareholders meeting in the penthouse suite of the swanky hotel we built in Minecraft (it’s our Slack channel), we discussed our favorite ASA articles of the past year. Because it is the season of listicles and we relish every chance to talk about ourselves, we decided to put them all together in one official post. Also, our site traffic is essentially zero at this time of year, so it seemed like an easy way for us to remember where we put them.

It was a great year for MLS (though perhaps not American soccer overall) and the most successful in our five year life as a website. We added interactive tables, introduced xPG, rebooted the podcast (new episode coming out soon! …probably), and added a lot of great new writers to our existing ranks of stale old writers. They’re not all represented in the list below, but special shout out to our weekly contributors who put together content every week - Little Things (@harrisonhamm21), Lowered Expectations (@harrison_crow), Expected Narratives (@ahandleforian), and Setting the Table (@ericwsoccer) - showed us the individual plays each week that made up the whole of the MLS season. We’d also like to extend a special thank you to Neil Greenberg of the Washington Post, for including us as a part of the WaPo’s incredible World Cup coverage.

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Evaluating Defensive Prospects for the Expansion Draft by Kevin Minkus

FC Cincinnati will face many difficult decisions over the next three months, as they build their expansion team to be ready for the 2019 season. Their next set of choices takes place today, in the Expansion Draft. What the team decides there may not make or break their season, but they do have the opportunity to add important pieces for their inaugural year.

One strategy, the path I’ll discuss here, is for Cincinnati to grab cheap, young players. The hope is that, while they weren’t key contributors for their former teams, those players will continue to develop. A team with enough of these works in progress, and with a sufficient capacity to develop them, might reasonably hope for a few to pan out into full-time starters.

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A Feast for Throws by Eliot McKinley

In Game of Throw-Ins, I characterized and introduced an expected throw-in possession retention model (xRetain) for MLS. Go read the whole thing, but it showed that throw-ins are more likely to be completed and possession retained when they are thrown backwards, quickly, and outside a team’s defensive third. But what are MLS teams and players doing with their throw-ins?

To help differentiate teams’ throw-in styles, I turned to hierarchical clustering (see the graph below). I won’t get into mathematical details, but you can think of it sort of like an evolutionary tree. However, instead of the branches separating species, they are separating different throw-in angle frequencies. Kind of like how humans and chimpanzees are near each other on the branches of an evolutionary tree but far away from birds, teams which always throw the ball backwards and short will be far away from those that always take throw-ins forward and long.

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Game of Throw-ins by Eliot McKinley

Much has been written and studied about set pieces in soccer. Penalty kicks have been Bayesed multiple times, I’ve analyzed free kicks in MLS and at the World Cup, corner kicks have been rigorously studied. But what about the humble throw-in? Aside from when teams develop a long throw-in program (see Delap, Rory) they are largely ignored or even ridiculed, in the case of Liverpool hiring a throw-in coach (see the first comment here).


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You Down with t-SNE? by ASA Staff

We all know that some teams play a certain style, Red Bulls play with high pressure and direct attacks, Vancouver crosses the ball, Columbus possesses the ball from the back. Although we know these things intuitively, we can use analytical methods to group teams as well. Doing so seems unnecessary when we have all these descriptors like press-resistance, overload, trequartista-shadow striker hybrid, gegenthrowins, mobile regista, releasing, Colorado Countercounter gambits...etc (we actually don’t know what some of these terms mean and may have made some up, but the real ones are popular so just google them yourself). Those terms are nice, but no qualitative descriptor can tell us how the styles of New York City and Columbus differ from each other. We need to measure, compare, and model two teams’ playing styles and efficiencies. If we are able to do these things we may be in a position to answer what style really is.

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Postseason Preview: NYCFC by ASA Staff

Article by @thedummyrun

Domènec Torrent is a fraud.

Just four months ago, when he took over New York City Football Club midseason from Patrick Vieira, the Catalan coach was hailed as some kind of tactical savant, fresh off a decade seated at the right hand of Pep the Father Almighty and come down to MLS to save us all. He promised to preserve Vieira’s system, which after all was vaguely modeled on Manchester City’s, and to make only incremental adjustments. He promised to compete for trophies—if not this season, okay, maybe next year. He promised us the pinaple would be pretty.

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