Turf and Injuries: The Data Hurts

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Turf and Injuries: The Data Hurts

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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Mapping Defensive Actions: A Spatial Analysis of Where Teams Focus Their Efforts

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Mapping Defensive Actions: A Spatial Analysis of Where Teams Focus Their Efforts

Every team has its own “style”. Some teams bunker, some teams high-press, some clog the middle, some work the wings. Where they defend is a major part of what defines their style. The recipe for a team’s defensive shape is one part tactics and 11 parts players on the field. Certain players seem to naturally gravitate their efforts to particular areas, be it the wing they’re assigned to, their preferred foot, their favorite partner-in-crime or how they’re instructed to approach the opposition. In the end, the action happens in consistent general areas of the field, but in complex patterns.

One could take an Opta map from any particular game and examine the defensive spatial patterns. You can see the clusters of defensive actions as well as voids where a team hardly seems to find themselves defending at all. But that’s just one game. We all know that teams are forced to adapt their style of play to their opposition, and whatever flukey circumstances played out in that game might not be totally indicative of a team’s overall style. What would really be telling is the aggregate over multiple games.

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Shots Not Taken: Exploring the propensity of teams to shoot from good positions

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Shots Not Taken: Exploring the propensity of teams to shoot from good positions

Do you ever find yourself yelling “JUST SHOOT THE BALL!” at the TV screen? Of course you do, you watch soccer! Sometimes it can be maddening to see your star striker make his/her way into the box, only to futz around with a pass or dribble. At times it doesn’t even matter whether that pass or dribble was successful. Does it seem like your team does it particularly bad? You’re probably not alone.

Psychologists will be quick to point out a thing called negativity bias. Basically, we probably all think our team dilly-dallies in the box more than others because we remember it better. The existence of this bias, by the way, is supported by a convincing amount of experimental evidence. But it begs the question, who is empirically more likely to shoot when they can?

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