Football is about scoring goals and not conceding them. For Culers, it’s also about how that ball arrives into the goal and the journey it takes to get there. But in terms of results, goals is the name of the game.
xG isn’t totally useless
Metrics like xG can be misused with when looking at a one game sample size. xG is the metric that determines how likely a shot results in a goal. Every xG value is between 0 and 1, with 0 being the most unlikely to score and 1 being a certainty. So shot with an xG of 0.4, as determined by factors such as the distance to the goal, the quality of the shot, and the angle, would be expected to go in 4 out of every 10 attempts.
With a large enough sample size, xG helps deduce which teams had a few things go their way on some goals, be it deflections, the sun in the keeper’s eyes, a nice wind; and which teams had things not go their way. For Barça, we can wrap up the first half of the season in two very different parts. Through the first 11 games, they exceeded their xG by 8 goals. Since then, they have underperformed their xG by 4 goals.
What about “luck”?
So logically, the bigger the sample size for a player and a team for the chances they create and score, the better xG is at being accurate in helping us quantify the unquantifiable aspect of football – luck.
Huge blowouts to start the season can be explained a bit by Barcelona capitalizing on “luck” in front of net. The recent results, where it often felt like the Blaugrana outplayed their opponent, showcases a lack of “luck”. In truth, if Barcelona start to score the goals they are supposed and miss the ones they would likely miss, their big chances created indicate that wins will come again. They won’t be 5-0 blowouts, but they should be wins.
Barcelona are doing the hard part well
If there is any hope in statistics, it’s the first list here. 85 big chances is absurd for the first half of a season in the league. Missing 50 of those is just as absurd. Still, 85 big chances created, even if that pace is unsustainable, should tell you that Hansi Flick has his team understanding the way they need to play. How they go about converting them, well that’s for him to figure out. Fortunately, while football can be fickle, teams that don’t create big chances don’t have anything to score and often can’t turn that trend around in a single season. Teams that do create big chances, as Barcelona do better than anybody in the world, just need to find a way to finish them.