After convincing wins over Real Madrid and Juventus in the previous rounds, the young Ajax team has drawn attention and could no longer be underestimated by its opponents. Spurs for their part were missing their two best goalscorers, Kane and Son, as well as Sissoko, the 6th most used player by Pochettino this season.
Ajax came out winner of this game in which both teams have shown two different faces.
The Lineups
Tottenham were announced in a 3-4-3 formation, which in reality was more a 3-5-2 with Lucas Moura supporting Llorente up front and a midfield three of Alli, Eriksen and Wanyama. Tottenham had played 13 times with a back three this season before this game, so it wasn’t a complete surprise to see them in this formation. However, it was probably more a forced decision for Pochettino than a choice given the players available.
No surprise from Ten Hag. Veltman started right back instead of Mazraoui who was just back from an ankle injury contracted against Juventus. Similar to their last games against Real at Bernabeu and Juventus in both legs, the shape would actually be a 4-2-3-1 with Van de Beek behind Tadic acting as a second striker in possession.
Tottenham struggles in the build up phase
Ajax were largely dominant in the first 20 minutes, with 64% possession, five shots and a goal. Tottenham were struggling to build up from the back and keep possession.
As expected based on previous games, Ajax started with a high pressing line.
In the video, we can see Ajax organisation out of possession. In their man-oriented zonal marking set up, the Dutch would match up man-to-man, causing the Spurs troubles to find passing options at the back and forcing them to often play back to Lloris. The French keeper would then most of the time look at playing long balls on his wing backs.
With a back three opposed to a front three pressing high like Ajax, these issues could have been anticipated. One of the main concept of the positional play is to create numerical superiority to progress with the ball. In this display, it is obvious that the defensive line won’t have a spare man to build up apart from the keeper. We should then see a midfield dropping deep to support the back three in possession.
In some instances, Wanyama would try to move to a deeper position, but he would be marked by Van de Beek. On the image below, we see Wanyama dropping to give an option. It’s important to note as well Alderweireld’s body shape, turning his back to the game, and therefore closing himself down under Ziyech’s pressure.
With such difficulties to create numerical superiority, an option would have been to use Llorente’s strength in the air to win challenges and second balls, which Spurs would do more often in second half.
If Tottenham were having a hard time building up from the back, they would equally struggle out of possession against Ajax’ fluid attacking system
Ziyech’s licence to move
In the first 20 minutes, Ajax delivered a masterclass in positional play rewarded by the only goal of this game. If the all team is to praise, Ziyech played a particularly important role in this phase.
Positioned as right winger on the team sheet, Ziyech would in reality be totally free to move on the pitch as he sees fit. Below are some examples of the positions he occupied during the first 20 minutes.
Striker 
Center midfield 
Left midfield 
Attacking midfield 
Left winger
While some coaches would typically ask their wingers to always stay wide when the ball is on the other side of the pitch to offer a switching option (e.g. Guardiola), Ajax would regularly leave the opposite wide area free to overload the strong side with as many players as possible and secure possession. Ziyech then had an essential role to play with his free positioning in possession.
With players roaming the pitch, it becomes difficult for a team to defend. In a zonal marking set up like Tottenham’s one, a player leaving a zone should then be marked by the teammate responsible for the zone he is travelling to. In practice however, a player travelling across zones frequently causes uncertainty in the defending team and is likely to be free of any marking, at least temporarily, or to to free a teammate up. Ziyech mostly positioned himself in a central attacking midfield position alongside Van de Beek. Both players would then overload Wanyama and create passing options in central areas. As a result, the Dutch’s goal came from Ziyech in a central position who could deliver an assist for Van de Beek.
Ziyech’s heatmap 
Ajax average positioning (Ziyech number 22)
Pushing the back three to its limits
We have already discussed the issues the back three had to face in possession, but it has also been tough for the Spurs out of possession. Ajax line up with a front three supported by Van de Beek, but as noted when presenting the line ups, the 22 years old player actually acts as a second striker, joining the front three whenever possible or rotating positions with Tadic who plays him as a false nine.
When a back three and a front three face each other, a wing back would usually drop to form a back four and maintain a spare man. Against Ajax, it is difficult to maintain this shape because of their constant movements and forward runs. In possession, Van de Beek has proven being excellent at managing space, reminding of Thomas Muller in some aspects. Against Tottenham, he again played an important role with the front three to create space between the lines.
Remember one of the main concept of positional play, numerical superiority. Ziyech’s movements across the pitch was one way to achieve that. Another way often used by Ajax and seen previously as well against Real Madrid and Juventus is to pin the defenders and prevent them from stepping up and pressing.
Above is an example of Ajax attacking structure. Pushing up with five players, they are forcing Spurs to defend with six players. More importantly, Wanyama has to drop to mark Neres, joining the back line and leaving his zone in the midfield. With their positioning, Ajax are removing layers from the Spurs’ defensive structure, opening up space in the midfield to allow penetration.
Few minutes later, Van de Beek will find himself a good position between Rose and Vertonghen, a position very similar to the one he will be in when scoring the only goal of the game.
On the play leading to the goal, Ajax have three players in the 18 yards box, with five Spurs’ players defending the box. The midfield line is flat, creating space between the lines with no cover.
Pochettino’s reaction
From the 20th minute, the Spurs’ coach adjusted the shape of his team in response to the Ajax domination. Tottenham switched to a 4-4-2 diamond, Vertonghen drifting to the left of the defence and Rose joining Wanyama and Eriksen in the midfield. Pochettino also asked Sissoko to warm up, presumably with the intention to bring him in for Rose. The Frenchman will actually come in for Vertonghen, after this one had to come off following a head injury. Rose had then replaced the Belgian as left back.
The change of formation clearly helped Tottenham to disrupt Ajax possession game, as well as get more control of the ball themselves.
In the build up phase, the Spurs would now have a spare man in their first line to counter Ajax’ pressing, giving them more time on the ball to create triangles and diamonds to progress through the thirds.
Sissoko brought in his work rate and energy in possession. The same way Van de Beek is essential for Ajax to create space, Sissoko’s forward runs would allow Wanyama and Eriksen to find pockets to receive the ball in midfield.
Sissoko’s forward run… 
to draw Tagliafico
Spurs’ unsuccessful possession
Spurs ended up the match with 51% possession after having only 36% in the first 20 minutes. Nevertheless, they couldn’t capitalize with a goal. There were different reasons to that.
With Spurs having more control of the ball, and their pressing being less efficient, Ajax were now positioned in a median block out of possession. It was therefore easier for Spurs to progress into Ajax’ half, but from there Ajax would be more compact and they would need to penetrate the block. To do so, Spurs would have need to stretch the pitch in its width. In their 4-4-2 diamond shape, they were suffering the lack of natural wingers though, relying entirely on Rose and Trippier (then Davies and Foyth) to provide width. In possession, Spurs would find themselves in a 2-3-2-3 shape with a narrow front three, allowing Ajax to remain compact at the back and matching up the midfield players with their 2-1 shape.
When Trippier or Rose would receive the ball, they would be forced to find a passing option in the centre of the pitch, but they were also facing a lack of support to overload Ajax wingers and full backs. They then played more often long balls toward Llorente, but with limited success.
Spurs were also very predictable in their attacking moves. With 44% of their attacks down the right wing and only 25% on the left wing, they didn’t move the ball enough in the width to disorganize Ajax’ block and change their angle of attack. This tendency to play mostly on the right wing was due to the players on the pitch though. Sissoko, who was playing right center midfield in the diamond, has played right midfield almost as often as center midfield in his career. Lucas, who played as a second striker, is him a natural right winger. Both are then naturally prone to drift towards the right wing. In addition, Alderweireld was positioned as left center back. Being right-footed, he would in general open up his body towards the right wing when pressed to be on his strong foot.
Finally, we can’t ignore Spurs’ individual performances. We could expect players like Alli and Eriksen to have more impact on the game. The overall technical level was slightly below Ajax’ players’ on.
Conclusion and outlook for the second leg
Ajax displayed two facets in this game. One the public would already know about after the Real Madrid and Juventus games, a very aggressive team when it comes to pressing, with an attacking mindset and a fluid positional play in possession. An aspect we didn’t really see in the previous four games though, was their capability to defend with a median block and a less aggressive pressing. Whether it was a choice to preserve the clean sheet, or a physical decline forcing them to back down, they have proven that they could also lay low and handle the pressure when needed.
In the second leg, Son will be back for Spurs. He has demonstrated its importance in the City clash, and with his absence against the Dutch side. Pochettino has probably learnt his lesson and will likely start with a back four in Amsterdam. The starting line-up could be the same as the one which started against Manchester City, with Son and Lucas up front, opening up the central area for Eriksen in the attacking phase. It will be a different challenge for Ajax against two very paced players. The question about Spurs remains the same though: how are they going to handle the lack of wide players in possession? Against Manchester City, they were facing a team who lost the first leg and needed to score, with a well-known willingness to dominate the possession. Hence they could proceed with counter-attacks, using mainly the half-spaces and not suffering the lack of width. Ajax though don’t necessarily have majority of the possession, and their result in London will not oblige them to open up more than they would usually do.
