Midway through the UEFA Champions League group stage, big questions ahead of the last-16

And just like that, we're halfway through the UEFA Champions League group stage. Blink a few more times, and it'll all be over.

The first three matchdays have been filled with both gloomy unpredictability (Manchester City destroying everything in their path, Bayern Munich treating the group stages like, uh, like the Bundesliga) and unexpected excitement. Napoli has won all three of their matches. Club Brugge won all three games! Chelsea fired their manager shortly after conceding their first goal to Dinamo Zagreb. Barcelona will spend another spring in the Europa League. And despite playing their home matches in Poland because their country is at war with Russia, Shakhtar Donetsk are this close to qualifying for the knockout rounds.

So, before the next three rounds fly by and everyone heads to the World Cup, let's use the halfway point to take a quick look at what's at stake over the next month of matches. Here are the most pressing issues confronting all eight groups, as predicted by FiveThirtyEight's prediction model.

Can Napoli win the damn thing in Group A?

Napoli has nine points from nine matches through three matches, a 98% chance of reaching the round of 16, and a 76% chance of finishing first. But they're not just winning matches; they're annihilating the opposition. According to FBref, Luciano Spalletti's team has the best goal differential (plus-13) as well as the best expected-goal differential (plus-7.8) of any team in the competition. 

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It's all because of "Kvaradona," baby. Khvicha Kvaratskhelia, a 21-year-old Georgian winger, is third in non-penalty xG and fifth in expected assists. Only Erling Haaland, who is on his way to fundamentally changing our understanding of how this sport works, has produced more combined xG+xA (4.2) than Kvaratskhelia's 3.0.

The frightening part is that Napoli has produced these performances against two teams that we thought would be pretty good at the start of the season. They thrashed Liverpool 4-1 in Naples before going on to beat Ajax 6-1 on the road in Amsterdam. Oh, and their star striker, Victor Osimhen, has only played 40 minutes in the group stages after being injured in the first half of their opener against Liverpool.

FiveThirtyEight currently gives Napoli a 4% chance of winning the Champions League, ranking them sixth in the world. If they repeat this over the three return legs, that number will appear far too low.

Can Club Brugge hold on in Group B?

This group is... well, it's awful. Atletico Madrid, ranked 13th in the world, has the highest rating in FiveThirtyEight's system. Group A, by contrast, has three teams in the top ten.

Of course, Atletico has been the worst team in the group through three games, both in terms of standings and xG differential. Meanwhile, Brugge, ranked 58th in the world (two places below Brentford), has the same number of points as Napoli, Manchester City, Real Madrid, and Bayern Munich. Only those four and Borussia Dortmund have a better chance of advancing.

The most important reason? Simon Mignolet – yes, that Simon Mignolet – has been flawless in three games. According to FBref, the average keeper would have allowed 2.9 goals from the shots he faced. The former Liverpool goalkeeper hasn't given up a single goal.

Furthermore, Brugge is scorching at both ends, with seven goals from 4.8 xG and zero goals conceded from 4.2 xG. However, with nine points in the bank and the other three teams squabbling for three points each, they may still advance even if they lose the rest of their matches.

Inter or Barcelona to advance from Group C?

Here are some quick numbers to set the scene for all of the return games in this group: Inter Milan has a better chance of advancing (54%) than Barcelona (47%), but Barcelona still has a better chance of winning the whole thing (5%). Surprisingly, Xavi & Co. are the second-favorites to win the Europa League (11%), trailing Arsenal (15%), owing to the increased likelihood of finishing third in their group.

I was wondering if Barcelona's defensively light and athletically limited midfield could hold up against Inter's strong unit a few weeks ago, but Marcelo Brozovic's injury essentially rendered that point moot. Instead, ahead of this week's match between the two teams, which will determine who advances from the group, the question has become: Can Barcelona create anything?

Barcelona and Inter combined for a truly pitiful 0.8 expected goals in last week's match at the Giuseppe Meazza: 0.6 for Barca, 0.2 for Inter. Given their three-point lead, I believe the Italians will settle for a similarly snoozy shot distribution at the Camp Nou on Wednesday.

Group D: Can Tottenham break the ice?

While Antonio Conte's team was unlucky to be tied for second after three matches, that doesn't mean they've been particularly bad. They've created 3.7 xG through three matches in a very weak group, which is the 17th-most of any team in the competition.

Now, as usual, their defense has been strong (1.9 xG conceded, fourth-fewest so far), and they have the best xG differential in the group. However, the risk of playing in a way that tends to limit chances on both ends is that you expose yourself to all kinds of variance. Spurs are the most talented team in this group, and research has shown that better teams win more matches when both sides have more chances. Could they benefit from a looser grip on the steering wheel?

Tottenham should be a nightmare matchup in the knockout rounds, but their ability to defend their own box and a handful of the world's best counter-attackers may be what keeps them from getting there. They began the group stage with a 76% chance of making it to the round of 16. After three games, that figure has dropped to 69%.

Who will win in Group E?

Isn't that a lazy section title? It only appears lazy because it is true!

Group B is the most "alive" group, with Brugge, Atletico Madrid, Porto, and Bayer Leverkusen all having a 31% chance of advancing. Group D is the most "compressed" group; the difference between first-place Sporting Lisbon (76%) and fourth-place Marseille (26%) is the smallest of any group. As a result, we'll call Group E the most "uncertain" group; Chelsea are the favorites to advance from the group, but at 66%, they're the shortest favorites, while FC Salzburg (61%), AC Milan (60%), and even Dinamo Zagreb (13%) all have legitimate chances of winning the group or at least finishing second.

While we're here, a quick shout-out to Dinamo Zagreb legend Mislav Orsic, who has two goals in the Champions League this season after shooting on sight in the Europa League the previous two seasons. Since the start of the 2020-21 season, here is his shot map in European competitions:

According to Stats Perform, he's scored 13 goals on 6.73 xG during this stretch of games. While I can't bring myself to use the phrase "Go off, king," it appears that a less self-conscious man than me might be able to do so here.

Can Shakhtar Donetsk win Group F?

Most people who aren't employed by an energy-drink conglomerate or weren't raised Catholic in Glasgow will be rooting for Shakhtar Donetsk, the competition's only Ukrainian team, in the final three matches. They are currently alone in second place, but FiveThirtyEight only gives them a 33% chance of advancing. Celtic is at 17%, while RB Leipzig is at 50%.

The good news is that Shakhtar has a one-point lead over Leipzig and a three-point lead over Celtic. At plus-two, they also have a five-goal differential advantage over Leipzig and a seven-goal advantage over Celtic. As expected, Mykhailo Mudryk, a 21-year-old winger, leads the way in nearly every attacking metric.

The bad: They have the tournament's fourth-worst xG differential (minus-4.3), trailing only Viktoria Plzen, FC Copenhagen, and Rangers. They've scored six goals on 22 shots and given up four on 65. That's not usually a winning formula, but given that they've already accumulated four points, they really only need to stay hot for another game or two.

Who cares about Group G?

City has a 91% chance of finishing first with nine points. Dortmund has an 89% chance of finishing second with six points. I can't recall a group that was so clearly won after only three games.

Group H: Benfica, you say?

Allow me to direct you to this piece for previous "Juventus stink" content. It hasn't gotten any better; on the contrary, it has gotten worse. Instead, consider this previously unthinkable possibility: Could Benfica be the best team in this group?

Roger Schmidt disappeared from high-level European soccer for a while after electrocuting the Bundesliga with a frenetic, high-pressing, high-shooting Bayer Leverkusen side that made Jurgen Klopp look like someone who played John Cage's "4'33" to get his players pumped up before games. He now has Benfica undefeated in the Portuguese league and undefeated (and tied) in their Champions League group after a two-year stint with PSV. Only Napoli, Manchester City, Real Madrid, and Bayern Munich have produced better xG differentials through three games.

Despite losing Darwin Nunez to Liverpool in the summer, they bolstered their midfield by signing River Plate's Enzo Fernandez, who completed all 72 of his passes against Rio Ave over the weekend. Now, normally, I'm not impressed by 100% completion rates – in fact, I don't care about completion rates at all – but this guy also created six chances and received an assist. He wasn't just doing backflips. This appears to be an impossible task!

Benfica have a 93% chance of advancing despite being tied with PSG on seven points. Whether they finish first or second will most likely be determined by what happens against PSG on Tuesday at the Parc des Princes.