October 02, 2019

Shots in the Dark: how data providers tell us different versions of what happened

October 02, 2019/ Eliot McKinley

Recently, this tweet created a small firestorm in the soccer analytics community. While it is unclear the source of the error, it was pretty clear that there weren’t 1,300 passes and 50 shots in an English League 2 match. This led to responses from prominent analysts such as StatsBomb’s Ted Knutson (including on his podcast [starts at 10:45]), Opta’s (and ASA alum) Tom Worville and Ryan Bahia, and Chris Anderson, author of The Numbers Game. All of them were saying pretty much the same thing: question the data you are using. If the data you are using to analyze a problem is not valid, then your solutions won’t be either.

So what do we know about the data that is used for soccer analysis? Previous studies have shown that people are pretty good at agreeing about what type of event occured in a soccer game (e.g. shots, tackles). But as far as I can tell, the accuracy and precision of locations of game events among the various data providers has not been studied. As Joe Mulberry pointed out when looking at the troubling inconsistencies between spatial tracking data and event data, small differences in locations can have big effects on downstream analysis including expected goals (xG) models. In other words, small inconsistencies in how data is tracked can have big consequences for the models built off that data. So what are the differences between how soccer data providers collect and report their data?

October 01, 2019

Trapp Game: How Caleb Porter has changed the Crew

October 01, 2019/ Cheuk Hei Ho & Eliot McKinley

The year 2019 brought a new Crew. Anthony Precourt got his wish and slithered away to Austin, while head coach and sporting director Gregg Berhalter began his rehabilitation of the US national team, leaving behind five years of solid results in Columbus. Replacing them was a new ownership group and front office led by the Haslam and Edwards families. Toronto FC’s Tim Bezbatchenko came in to lead the Crew’s soccer operations and former MLS Champion Caleb Porter took over as the head coach. With the smallest offseason turnover of a perennial playoff team, expectations were that Porter would provide a steady hand for continued success this season. However, that hasn’t happened and Columbus remains third to last in the Eastern Conference with only a game left in the season. Did the transition fail to succeed because Porter couldn’t implement his vision, or because that vision just didn’t work?

September 26, 2019

Lowered Expectations: What the Whitecaps are doing wrong and Vako is doing right

September 26, 2019/ Harrison Crow

The premise of this column, for anyone new, is that we take the five highest valued shots from open play according to our expected goal model, and dissect the plays while talking about the players, the teams, and how our model works (or sometimes doesn’t). Sometimes I just yell into the wind about crossing.

Let’s see what we’ve got.

September 25, 2019

The Price is Right! How Jack Price fits the Rapids, and the Rapids fit Jack Price

September 25, 2019/ Alex Bartiromo

Amidst another difficult season for the Colorado Rapids, a few changes have provided hope for the club and its supporters. Sacking Anthony Hudson was long overdue after a season and a half of shaky leadership, poor results, and a feeling that the team was falling behind newer and better run MLS franchises. The change in manager, plus the addition of various proven MLS vets like Nicolas Mezquida, Clint Irwin, Sam Nicholson, and Keegan Rosenberry; undervalued young talents such as Lalas Abubakar and Jonathan Lewis; and the development of homegrown talents Cole Bassett, Sam Vines, and Sebastian Anderson has reinvigorated the squad and given fans hope for an improved season in 2020. However, this has left many of the players acquired under Hudson in limbo. Will they form a part of the Rapids core moving forward, or will they be victims of another Rocky Mountain rebuild? One player who has proven his value to the team—albeit in an unusual way—is also one of the least talked about around the league. That player is Jack Price.

*Hold for applause*

September 24, 2019

Fear and Desire: TV Ratings, Revenue, and MLS’ relationship with the Latinx Community

September 24, 2019/ Mark Asher Goodman

There’s a great little line of dialogue in the 1993 film ‘True Romance’* where Christian Slater tells Saul Rubinek “You have to come to terms with your fear and desire.” This is a phrase I love so much that I would put it in a sermon, if it weren’t for the fact that there’s simply no good way to quote Quentin Tarantino from the pulpit.

Fear and desire - that is the perfect expression for MLS' odd relationship towards the domestic Latinx** market. It also applies well to how MLS and Mexico's Liga MX soccer begin out their strange and exciting new venture, as the two have planned for an expanded 'Leagues' Cup' competition, and are exploring the possibility of interleague play and perhaps more.

September 23, 2019

ASA Roundtable: Defensive Actions

September 23, 2019/ Alex Bartiromo

Here at American Soccer Analysis we try to publish cutting edge articles on soccer that don’t rely on narrative, anecdote, or lazy comparison, preferring instead to rely on data, experimentation, and a ruthless questioning of all of our own previously held beliefs. As you might surmise from this somewhat pompous description, doing that is hard, and our writers have more opinions and insights than we could possibly publish. That is why we are coming out with a new series, the ASA roundtable, a weekly discussion between our contributors on questions facing the soccer and soccer analytics communities today. We look forward to your feedback, and if you want to submit a question just tweet it to @analysisevolved or email us!

September 20, 2019

Lowered Expectations: Shot Stopping and Model Design

September 20, 2019/ Harrison Crow

Has it really already been a week?

Well, if you’re at all familiar with this article you know what we’re about shots, shots, shots. It’s almost as if we starred in a LMFAO video with Lil John 10 years ago and never quite got over it (we didn’t). The closer to the goal the shot is, the better. I know that sounds obvious but this is a very scientific process and is incredibly complicated

Thank god, we have this blog where we can unravel the deep seatedmysteries of expected goals and explain how we distill these goal scoring opportunities down into cold raw values which we’ve learned can now entirely explain the game of soccer.

Let’s get started.

September 17, 2019

xPG is Back, Baby!: Putting Possession Metrics to the (Correlation) Test

September 17, 2019/ Jamon Moore

Last year, Cheuk Hei Ho, Eliot McKinley, and I collaborated on a soccer metric called Expected Possession Goals (xPG). xPG is a possession-based non-shot expected goals metric designed to measure the value of possessions whether they result in a shot or not. You can read more about it in these initial articles here on American Soccer Analysis. Later last season we extended xPG into multiple variants, including measuring possession risk and mistakes, but so far the initial xPG, now called Chance xPG, has been the most interesting. We even created a Twitter account called @GameFlowxPG which measures match momentum. It has been pretty popular (I’m a little salty since it usually has more followers than I do).

September 13, 2019

Lowered Expectations: The International "Break"

September 13, 2019/ Harrison Crow

I know that everyone is pretty wrapped up with the International Break and how awesome it has been for those in North America between Canada winning twice, Mexico looking like a world power, and the US ... well, two out of three isn’t bad right?

But don’t forget we had Major League Soccer last weekend! So let’s talk about that and the happiness associated five missed golden opportunities, as we do every week. Let’s get it!

September 06, 2019

Lowered Expectations: Katai is Fired Up

September 06, 2019/ Harrison Crow

You may or may not remember that I like to write about how shots from good locations don’t become goals. This was, once upon a time, a weekly feature here. Drew has begged me to come and start writing again, so here we are back again.

Those of you who may not be familiar with this column of mine, please, allow me to introduce to you the idea of expected goals. It’s the probability a given shot attempt would be scored, taking into account specific criteria captured at the time of the shot.

In this column we like to talk about what the expected goals model sees, and also what it doesn’t, when arriving with the xG number. The theme of this column is to take the five highest probability shots from open play (i.e. excluding free kicks and set pieces) of the previous week that didn’t end with the ball in the back of the net.

It also often turns into me decrying terrible crosses into the box that the model likes but are in actuality terrible chances that are awful and stupid and should be outlawed. Okay, well... let’s get started!