Bellingham to Wirtz: The best U21 outfield stars this season

When Lamine Yamal was born, Rihanna's "Umbrella" was the No. 1 song in America and, basically, the world. Pau Cubarsí was all of 6 months old at the time.

Yamal and Cubarsi are 16 and 17 years old, respectively -- and they've been two of Barcelona's better players in recent weeks and months. With Yamal having already made four appearances for the Spain national team, Cubarsi will likely make his debut on either Friday (against Colombia) or Tuesday (against Brazil). Against Brazil, they might face Endrick (17 and bound for Real Madrid this summer), or Girona's Sávio (19) and Yan Couto (21).

Florian Wirtz (20, Bayer Leverkusen) and Jamal Musiala (21, Bayern Munich) might be the two most important players on the Germany national team. Warren Zaïre-Emery (18, Paris Saint-Germain) made his national team debut for France last November and scored. Jude Bellingham (Real Madrid) has already made a €100 million transfer and more than 25 appearances for England and he won't turn 21 until late June.

This is appalling. What had you done by age 21? Anyone who clicked on this piece should feel older and more decrepit for it. But throughout both world soccer and European club soccer, the youths are taking over.

So, who's doing the best job of that in 2023-24? To answer that question, we're going to use a pair of advanced stats -- xG and xPVA -- and apply them to players aged 21 or under right now.

The former you've probably heard of by now: xG, or expected goals, is derived from StatsPerform's model for how likely a shot attempt is to go into the net. A penalty is about 79% likely to go in, so it's worth 0.79 xG while a long-range bomb with half the defense in front of you is more like 1%, or 0.01.

The other measure, xPVA, isn't quite as widespread yet. Based again on StatsPerform's models, it looks at the expected value added for a given possession by just about any player action, like passes, 1v1s, etc. It rewards ball progression -- it is essentially an attempt to measure everything that happens before the shot, and it rewards players like Manchester City's dribble-dominant Jérémy Doku (+8.9 xPVA, most in the Europe's "Big Five" top leagues) and extreme ball progressors like Arsenal's Bukayo Saka (+8.0), Newcastle's Kieran Trippier (+7.1) and Wirtz (+7.0).

Combine it with the shot value itself, and you've got a decent value measure, yeah?

The list of xG+xPVA leaders in Europe's Big Five leagues in 2023-24 is basically a "best players in the world" list: Bayern's Harry Kane currently leads the way with 28.6 combined xG and xPVA, followed by Kylian Mbappé (22.6), Erling Haaland (22.0), Mohamed Salah (21.5), Loïs Openda (20.4), Bukayo Saka (19.6) and Lautaro Martínez (17.9). It is an attacker-friendly measure, to be sure, but it tells a pretty interesting story.

What can xG+xPVA tell us about the players aged 21 or under? It may be an attack-focused measure, but let's look at the leaders at each outfield position -- goalkeepers obviously don't qualify here -- on the pitch.