Champions League: Can Monaco Upset Juventus?

Monaco versus Juventus is certainly the more surprising of the two remaining Champions League ties.

After qualifying for the competition by finishing third in Ligue 1 and topping its group, Monaco pulled off a pair of knockout stage upsets by eliminating both Manchester City and Borussia Dortmund.

Five-time reigning Serie A champion Juventus might not exactly fit the plucky underdog role itself, but its thrashing of Barcelona in the quarterfinals was certainly a surprise. The "Old Lady" beat Barca 3-0 in Turin and then advanced after a 0-0 draw in Spain.

The Italian giants are currently heavily favored to make it to their second final in three seasons, with the betting market giving them about a 70% chance to advance. As for Wednesday's first leg in Monaco, Juventus have been given about a 40% chance of winning, compared to a 33% chance for the hosts, with a draw making up the difference.

Does Monaco Have an Answer for the Juve Defense?

A frustrating reality of contemporary soccer punditry is that national stereotypes still seem to hold a lot of sway. Fortunately in this case, the Italian club really is bringing an elite defense to the table. Juventus boast one of the stingiest defenses on the planet, with a strong backline reinforced by the legendary Gianluigi Buffon in goal.

The Bianconeri have only allowed 22 goals in league play this season (0.6 goals per match) and are the best defense in Italy any other way you choose to measure it.

They lead the Italian top division in shots allowed per game (9.2), shots inside the penalty box per match (4.5), and Opta-defined "Big Chances" allowed (19; the next best team in Serie A has conceded 34). Juventus are one of 12 teams in Europe's top five leagues (the Premier League, La Liga, Serie A, the Bundesliga and Ligue 1) that has conceded fewer than 10 shots per match.

An advantage in terms of possession has certainly helped here (Juventus are fourth in the league with a 55.2% possession rate), as opponents see less of the ball and therefore have fewer opportunities to get shots off.

That said, the backline, led by veteran center backs Giorgio Chiellini, Leonardo Bonucci and Andrea Barzagli, have done exceptionally well to limit the damage when the opposition does create a chance. More than half of the shots Juventus have conceded have come from outside the box, and no other team in Italy can say that. Also, only 6.1% of the shots against the Bianconeri have been Big Chances; this is magnitudes better than the next best team (the gap between Juventus and second-place Roma here is equivalent to the gap between Roma and 10th-place Crotone).

Overall, Juventus have the best defensive rating among the top European leagues in terms of FiveThirtyEight's Soccer Power Index, which suggests the club would hold average sides to 0.5 goals per match.

Juventus probably presents Monaco’s high-scoring attack with its toughest test of the campaign.

By simply looking at goals per game, the Ligue 1 side certainly seems up to the task, as it leads the league with 95 goals (2.8 per game), which is nearly three standard deviations above the league mean.

It might not be so simple, though, as Monaco have reached this high largely via a sky-high conversion rate of 19.4%. Shooting percentage is very inconsistent from match to match, and Monaco have been good, but not great, in terms generating chances. The side is averaging 14.4 shots per game, which is about 1.4 standard deviations above the mean.

Monaco have not entirely fluked its way into this high shooting percentage, of course, as it has taken 64% of its shots in the box and features the attacking talent of Falcao (19 goals in Ligue 1, 5 in the Champions League) and Kylian Mbappe (14, 5).

Then again, if we look at FiveThirtyEight’s shot-based expected goals model, Monaco have averaged about 1.8 expected goals in league play. This is still good, but it is a far cry from what they have actually done so far, and this could be problematic for the side, given that expected goals predict future performance better than actual goals.

It is also worth noting that Monaco will probably look to cede possession to Juve and look to attack on the counter. In domestic play, the club own a 51.4% possession rate (6th in the league), but in Europe its possession rate drops to 45.8%, which is tied for 22nd in the 32-club tournament (excluding the qualifying rounds).

They've had success with this approach, but it remains to be seen how effective it will be against Juventus, who have yet to concede a goal on the break in the Champions League and have only allowed two such scores in league play, per WhoScored.com.

At the Other End of the Pitch

Monaco are not the only team with an attack that is outscoring its shot-based metrics. Juventus are seventh in Serie A in shots per match (15.0) but third in the league in goals per game (2.1).

A 12.6% conversion rate explains much of the difference (along with 5 own goals from its opposition), but unlike Monaco, much of Juve’s elevated shooting percentage can actually be chalked up to quality chance creation.

The Bianconeri take 63% of their shots inside the penalty area, and they are third in Serie A in both Big Chances created per match (2.3) and Big Chances per shot (15.0%).

In terms of FiveThirtyEight’s shot-based expected goals model, Juventus “should” have about a 1.9 goals per game average. Gonzalo Higuain leads the way with 23 goals and has formed a solid strike partnership with Paulo Dybala (9 goals, 6 assists).

They will be opposed by France’s number two scoring defense, which has conceded 0.9 goals per match. Monaco have actually allowed a worse-than-average percentage of shots in the box (61%), but since the club is only allowing 9.5 total shots per game, this has hardly mattered.

Also, in the Champions League, despite their possession disadvantage, Monaco have still managed to hold opponents to 10.0 shots per game.

The unit should be able to at least slow the Juventus attack, but it will have very little margin for error, given just how stout their counterparts from Italy are.

If Falcao and Mbappe can continue to defy the odds and convert at an extreme rate, this will be an incredibly close tie. But if this outlier of an attack regresses to the level implied by the statistics, expect Juventus to march on to Cardiff.