When Ajax and Spurs kick off in their shock Champions League semifinal match on April 30, it will be nearly 10 months since Ajax began their Champions League campaign. The Dutch runners-up entered the competition in the second qualifying round, opening on July 25 at home against Austrian side Sturm Graz. They won 5-1 on aggregate and then defeated Standard Liege of Belgium and Ukraine’s Dynamo Kyiv on their way to the group stage.
Tottenham’s path to the semis is, if anything, even stranger. After the first three group stage fixtures, from which Spurs took one point from nine, FiveThirtyEight gave the team a 12% chance of making it out of the group. But thanks to a massive turn in their own form along with a bit of help from Ajax’s Dutch rivals PSV, who drew against Inter Milan on the final match day, Spurs made it to the round of 16.
This is Tottenham’s first ever time in the Champions League semifinals. It is also the first time a team from outside Europe’s top five leagues has progressed this far since PSV reached the semifinals in 2004-05, falling 3-3 to Milan, with the Italian giants advancing to face Liverpool in Istanbul. The last time a team from outside the big five made the finals was when Jose Mourinho’s Porto won the tournament in 2003-04. So everything about this matchup is deeply weird and unexpected.
That being said, if you look at the tactical battles, things start to become a bit more predictable. Both teams have fairly established ways they prefer to play this season.
Ajax, in vintage Dutch fashion, set up in a 4-3-3 with center halves and midfielders who are all comfortable with the ball at their feet. Their most regular center back pairing features the up-and-coming Mattijas de Ligt alongside veteran ex-Man United man Daley Blind. Up top they are led most regularly by the attacking threesome of Hakim Ziyech, Kaspar Dolberg, and ex-Southampton attacker Dusan Tadic. The three have combined for 51 goals in the Eredivisie alone this season.In recent weeks, David Neres has become a more regular presence in the team, taking a spot on the wing with Tadic moving into a false nine role in place of Dolberg. That is the trio that took the field in both legs of the quarterfinal tie with Juventus. Given that the line between a 4-3-3 and a 4-4-2 diamond has always been a little blurry in Dutch football, this move isn’t terribly surprising and is reflected in the passing charts you can see in recent Ajax matches. Here they are against Juventus in the second leg of the Champions League quarterfinals:
As you can see, Tadic has dropped off into a deeper role than wide forward Neres, as much a number 10 as a true striker, while Ziyech and Neres tucked into narrow wide attacking roles and combine with the nominal striker. The players that link midfield to attack are Donny van de Beek and Lasse Schone, who scored the free kick goal against Real Madrid that conclusively buried the three-time defending European champions in the round of 16.
This system is a fairly consistent one for the Dutch side. Here is another passing map, this one from their recent league victory against Willem II:
While it can be a little difficult to parse the midfield positioning, the shape, whether domestically or in Europe remains a 4-3-3 morphing into a 4-4-2 diamond.
The engine for the Ajax attack is Barcelona-bound midfielder Frenkie de Jong. You can see that in both charts above, as de Jong is the deepest midfielder and is used both as a bit of a possession metronome and as a primary ball progression outlet as he consistently supplies both the striker, Tadic, and his more aggressive midfield partners Schone and van de Beek. de Jong averages 14.57 deep progression per 90 minutes in the Eredivise far outstripping his teaamates. The only other player with double digits deep progression numbers in Daley Blind with 10.67, but Blind attempts more long balls, 4. whereas de Jong is focusing more on short, progressive passes into the central attacking zone.
The key for Ajax is successfully progressing the ball into the attacking third. Once they have done that, the creativity of Tadic and Ziyech has been a nightmare for opponents to deal with. Ziyech is currently averaging 2.17 open play key passes per 90 minutes while Tadic averages 2.5.
Not only are the Dutch giants dangerous with the ball in the attacking third, they’re also dangerous when the opposition has the ball in their own defensive third. Here is a defensive heat map for the Eredivise this season:
The Champions League map is similar, though not quite so extreme:
There is, in fact, an argument to be made that this Ajax side is built a bit like Luis Enrique’s Barcelona: They have elite technical players across the pitch, they focus on progressing the ball into the attacking third quickly, and once it is in the attacking third they rely on an aggressive press and elite playmaking attackers to create a high volume of quality chances.
Telling a single story about Tottenham’s tactics this season is impossible. Virtually the entire squad has missed significant chunks of time due to injury. If you define the core of this season’s Tottenham as Hugo Lloris, Jan Vertonghen, Toby Alderweireld, Moussa Sissoko, Dele Alli, Christian Eriksen, Son Heung-Min, and Harry Kane (which leaves the fullback roles and one midfield role open to rotation around this general core) then Tottenham’s core have started together in four of the club’s 53 competitive fixtures. Those seven players have also all appeared in four additional competitive fixtures, though they did not start together. Those four games in which they have started include two league fixtures and two European matches.
Because of how irregular the Tottenham best XI has been this season, it’s hard to say anything that can be backed up with a high degree of certainty and analytics. The team just hasn’t been stable enough due to the lack of summer signings, World Cup hangover, international duty, and general injury issues.
That being said, you can still discern some themes in how this version of Tottenham want to play. The defining problem for Spurs this season is that the team basically has no midfield. Eric Dier has missed most of the season, Mousa Dembele had limited minutes before being sold to China, Victor Wanyama has struggled for fitness, and both Harry Winks and Moussa Sissoko are not vintage Pochettino midfielders. So Tottenham’s tactics this season have, by necessity, been reactive and specifically a reaction to the problem of not having a midfield.
How has Pochettino dealt with this? At Cartilage Free Captain, Joel Wertheimer, has likened Pochettino’s solution to a soccer version of the “air raid” offense often seen in American football. The idea behind the air raid is that you eschew shorter plays and consistently attempt more aggressive, direct attacks. But this isn’t a hoof-it-and-hope strategy. It’s a considered tactical approach that recognizes a few key things:
Given those factors, we have seen a predictable shift in Tottenham’s play this year. In the past the team played a relatively high block system and attempted to squeeze the game into the attacking half or even attacking third. The system depended on having attackers willing to press, midfielders who can sweep up what the attackers miss, and defenders who are generally excellent and are especially comfortable playing a high line and have the judgment to know when to step up and when to drop off. When the team included Dembele and Dier in midfield (or a fit Victor Wanyama) this system worked. But with all three unable to contribute at their peak level this season, the team needed a rethink and that is what Pochettino did.
The defenders now play a middle block—it’s not a deep-and-narrow countering style like Simeone’s Atletico or a vintage Mourinho team. But it also is not as high a line as in previous years under Pochettino. This is necessary because if the first line of the Tottenham press fails to win the ball, there is no second line to sweep up. Because of that, playing a high line would be suicidal.
There is a second benefit to playing a deeper line: It stretches the opposition and creates the mismatches that Spurs can exploit whenever Jan Vertonghen or Toby Alderweireld are able to quickly advance the ball into the attacking third.
The result of this system is reflected in the data. This heat map shows where Spurs defensive actions take place relative to the rest of the Premier League. As you can see, the front wave of the press still wins back the ball a lot in attacking areas, but if teams break that initial wave they are likely to progress the ball into the Spurs attacking third, as Tottenham basically does not defend in midfield.
When Spurs are at their best, their front line is buzzing around disrupting the opposition buildup and creating quick-developing chances off the fast build-up play facilitated by Alderweireld, Vertonghen, Sissoko, and, sometimes, fullbacks Danny Rose and Kieran Trippier.
As you may have noticed, there is some overlap here between how the two teams want to play. Both want to keep the ball in the attacking third as much as possible, both have a forward line that likes to press and win back possession, and both rely on a couple deep lying playmaker types to handle much of their ball progression into the attacking third.
That being said, whereas Ajax does much of this through an elite midfield built on de Jong progressing the ball through the middle of the field to a couple box-to-box midfielders or a false nine, Spurs do it through the running of Rose or Sissoko and the passing of Alderweireld and Trippier. And while Ajax look to work the ball around inside the attacking third, Spurs play far fewer attacking third passes because their chances come very quickly after the ball has entered the final third. Given these stylistic points, a few matchups are likely to be especially important.
With Harry Kane and Moussa Sissoko injured and Son Heung-Min suspended for the first leg, Spurs will have to play a makeshift attacking line. That being said, we’re likely to see a 4-2-3-1 / 4-4-2 diamond hybrid with Eric Dier, Victor Wanyama, Dele Alli, Christian Eriksen, Lucas Moura, and Fernando Llorente as the six forward players for Spurs. The team could also drop Llorente, play Lucas up top, and go for a 3-4-3 system with Dier and Wanyama in midfield and Dele and Eriksen supporting Moura. In either case, Dele, Eriksen, and Moura are all capable high pressers who could potentially disrupt de Jong, Blind, and de Ligt as they try to build the Ajax attack from the back. If Spurs can limit what Ajax’s deeper playmakers can create, it could strangle the Ajax attack before it can start.
Neres, Tadic, and Ziyech all excel at playing tidy possession football in the attacking third, culminating in the creation of high-quality chances in the box. However, Vertonghen and Alderweireld, both former Ajax players who were partners in defense in Amsterdam before moving to Spurs, are both elite defenders who read the game well, anticipate opposition movement, and position themselves well to defend in the box.
That being said, Ajax is likely to have a lot of chances to run at their former defensive pairing. The lack of a midfield means that once the initial attacking press is broken, there is very little between the Ajax attackers and the Tottenham defense. It is probably not too much to say that the winner of this tie will be determined by how well Vertonghen and Alderweireld defend against their former team.
It’s not just in defense where Tottenham’s two Belgian defenders figure to have a large impact on this tie. They also will play a major role in the Tottenham attack. If the defense can successfully progress the ball rapidly—which will be even more important since Sissoko’s ball progression in midfield will be missed in at least the first leg—then Spurs are likely to be able to create a lot of chances. Ajax’s back line is much less solid than Tottenham’s and so while Spurs can likely afford to cede some possession to Neres, Ziyech, and Tadic, one suspects that Ajax will be far less willing to give Dele Alli, Christian Eriksen, and Lucas Moura similar time on the ball in attacking areas.
The most unlikely Champions League semifinal in at least a decade may also be one of its most interesting ties. This Ajax side is the best non-big five team in Europe since Jose Mourinho’s Porto won the European crown. Spurs, meanwhile, are continuing to thrive thanks to the genius of Pochettino, the defensive excellent of Vertonghen and Alderweireld, and the fact that even if they never play all their elite attackers together due to injury, the one or two that are available keep delivering in clutch moments. If those trends continue, we will likely see the north London side making their first ever trip to the Champions League final. But if Dele and Eriksen struggle or the Belgian duo at the heart of the defense falter, Ajax will be headed to Madrid, looking to win their fifth ever European cup–a total that would bring them level with both of their potential opponents in Madrid.
Header image courtesy of the Press Association