Two rounds down, two more to go, and then the real action starts: knockout rounds! Read up on last week’s goalkeeping round up here, if you’re a true goalkeeping nerd.
1.) Alyssa Naeher (Chicago Red Stars) - Naeher wasn’t featured against the Portland Thorns. Return later in the week for a recap on round three or scroll down to see how Emily Boyd and Cassie Miller did in her stead.
Read MoreLast Saturday, the North Carolina Courage’s Denise O’Sullivan ushered in the return of professional team sports in the United States after several months, with the first strike of the ball in this summer’s NWSL Challenge Cup. At roughly the same time, we haphazardly struck a few keys on our computers, proudly ushering in a set of exciting changes to ASA’s interactive application. This allowed us to share some new features, most importantly NWSL data and our goals added (g+) values for all players in all seasons for which we have data.
Read MoreIf there is one thing that 2020 has taught us so far, it’s that viruses are incredibly difficult to defeat, and that the math around them is difficult to calculate and convey -- much, much more difficult to create and understand than, say, an expected goals model in soccer. This is why months after COVID-19 emerged experts are still arguing over the data related to testing, cases, and hospitalizations, not to mention treatment options.
We are not epidemiologists, but we do like our data. While there probably should not be an MLS is Back tournament in Orlando starting this week, at this point there will be, and once again the math is causing problems for MLS. While MLS HQ fixed the issues with how teams advance out of groups, COVID-19 in the Disney World MLS bubble (The Bubble) is not solved so easily.
Read MoreRound one of the NWSL Challenge Cup didn’t give us much time to rest, and round two kicked off just 10 hours after the opening round’s conclusion. For this recurring string of posts, we’ll be looking at the goalkeepers’ performances in the tournament and (power) ranking each one’s chances of being named the Challenge Cup’s best goalkeeper. At the end of the tournament, we’ll name ASA’s top goalkeeper of the tournament. We’re in the early stages right now so it’s still anyone’s game, but here are the NWSL Challenge Cup goalkeeper power rankings after round one.
Read MoreThe time has come. This weekend, the NWSL will return as the first professional sports league in the United States to take the field since the COVID-19 pandemic began. After writing previews since before the Challenge Cup was even announced (here are parts one and two), we’re excited to share our final set on the last three teams in the league.
Read MoreIn the time since the first round of mini-previews, the 2020 NWSL season has taken the form of a short tournament called The Challenge Cup, which is to be played from the end of June until the end of July. Many questions remain about how the competition will shape up, including which players will ultimately choose to participate. In this edition of mini-previews, we travel out west to preview OL Reign, Portland Thorns, and Utah Royals FC. From name changes to significant roster overhauls to new coaching staff, each of these teams has something new in store for the upcoming season.
Read MoreHi everyone, welcome to our 2020 ASA Goals Added coronavirus roundtable spectacular!! In this roundtable, you will have a chance to read about the hottest new innovation in the analytics world, already spawning imitators across the world before it’s even rolled out. But what is Goals Added (g+) and what can it teach us about the beautiful game that past metrics weren’t able to? To discuss this topic, we have some of the world’s foremost experts, the people who built the dang thing. Welcome, everybody!
Let’s start from the beginning. Readers can read about the g+ model and what it measures. What are the origins of this project and why did you start working on it? I read somewhere that it has been in the works for five years! Has it evolved over that period? Are you asking the same questions you were then? What does g+ allow us to do that we weren’t able to before?
Read MoreAs you may have noticed with this week’s rollout of goals added (g+) and the related articles, we at ASA are pretty fired up about our new possession xG framework and player valuation methodology. The journey to get to this point would best be documented by the thousands of messages in the ASA slack chat over the last 9 months, and something I want to highlight is that the exercise of putting together this model would have been worth it in and of itself for all involved even if nothing was ever published.
Read MoreThere’s an old xkcd where a guy standing on top of a giant trash heap of math symbols explains how machine learning works: you dump your data into this junk pile here, see, and answers fall out the other end. And if the answers are wrong? “Just stir the pile until they start looking right,” he shrugs.
Models like goals added (g+) are great at answering wildly complex questions like “How much did this left back’s whiffed tackle at the halfway line change his team’s mathematical probability of scoring next time it gets the ball?” but terrible at telling you how they did it. In that sense the model is sort of like the athletes it’s trained on, guys who get a face full of microphones after every game but, as David Foster Wallace once wrote, “usually turn out to be stunningly inarticulate about just these qualities and experiences that constitute their fascination.” What were you thinking when you derived that bizarre possession value? Well, Sebi, it’s not the result we wanted but we’re just trying to take it one calculation at a time. Thanks to the fans for believing in us.
Read MoreLook at that. Pretty, right? The colors. The font. The icons. The logo. That tiny beeswarm. All work together to make a pretty damn good visualization. But these things just don’t emerge from a computer fully formed, they take a lot of effort and there are a ton of ways that things can go wrong. Inspired by Peter McKeever’s discussion of his beautiful diamond plots, here are the decisions we made and iterations of this viz along the way to what you see above.
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