We finally saw a glimpse of a system that might be able to stop Chelsea when Tottenham decided to flush everything down the toilet. A match between London teams at Stamford Bridge ended with yet another win for, what seems to be, unstoppable Chelsea.
CONTEXT
Teams went into the clash from quite different mental positions. Chelsea was on six games winning streak that started in September with heavy loss to Arsenal and change of formation to 3-4-3. High on confidence with standard line up where everyone knows what to do.
Tottenham, on the other hand, is still sore from Champions League in midweek and only one win in last five Premiership games. Unlike Antonio Conte, Mauricio Pochettino had to replace suspended Danny Rose and opted for Kevin Wimmer who started only two games in the league.
TOTTENHAM GAME PLAN
Despite psychological disadvantage, Tottenham started admirably at Stamford Bridge.

As you can see above, Tottenham was defending from front trying to force a misplaced pass or at least an uncontrolled clearance to regain the ball and harass the build up from Chelsea.
However, what made Tottenham look so good in the first half was movement of their players and the way they were able to exploit Chelsea’s weakness in a way nobody has done since they dithced to 3-4-3.
IN POSSESSION
The idea of Pochettino was to overload the left flank and exploit attacking mentality of Chelsea right wing back Moses on counter attacks. During positional attacks Tottenham would still overload Chelsea right flank and look to use quick passing between front four to get around the defence- If this wasn’t possible they would look to change the point of attack to Chelsea weak side directly passing to Walker or via a back pass.

Above is the situation where Chelsea is all set in defence. However, speed and technical ability of Alli to burst by his marker from deep allows them to progress into the attacking third. Crucial is the positioning of Heung Min who is sitting on touchline while Kane also moves towards left. This ties down Moses and Azpilicueta forcing David Luiz to close down Alli. Chain reaction continues as Brazilian leaves his position in the defensive line opening space for Eriksen who cuts inside from right and scores for early lead.

The same pattern is used on counter attacks as well. Above is Heung Min receiving the ball while Moses fails to track back in time. Eriksen leaves the right flank to Kyle Walker and moves into central position to create 4v3 overload.
This kind of movement and overloads created in left half spaces were creating all sorts of trouble for Conte’s team that couldn’t cope with them once first line of defence was broken.
So why was the second half so much different? Chelsea did find an equalizer through sheer magic from Pedro and that certainly lifted the team in the half time. However, it did help but doesn’t explain why Tottenham failed to produce same movement.
Match stats shed a bit of light there, though. If we look at positions where front four Tottenham players received the ball in the first half and compare it to the second period, we realized how Pochettino changed his approach after the half time. And failed.
CHANGES IN THE SECOND HALF
Analysing the positioning of most attacking Tottenham players, we can see that in second half they were occupying different spaces compared to first half.

Above graph was created with data from positions in which each player received the ball. The emphasis on left flank from first half has obviously shifted to the opposite side in the second part of the match.
What this tells us is that Heung Min changed places with Alli while Kane adopted traditional striker role in the middle of the pitch. This meant he abandoned exploiting Moses’ attacking mentality and shifted his players to right. However, as Kane was firm in the centre of the pitch, Tottenham couldn’t create numerical advantage so consistently and failed to threaten the hosts.

If we take a look from which side Tottenham approached the game we can see that second half meant they have abandoned the left flank and shifted over to the right. As we have seen in image before, without Kane drifting to right, this wasn’t creating gaps between Chelsea centre backs and Tottenham lost the edge.
It is difficult to say why would Pochettino make such a change in the half time. Maybe he was expecting Antonio Conte to react and cover his right flank better while surprising him by a hit on the other side. While Pedro was more engaged in defensive duties by helping Moses, Conte didn’t significantly change his approach during the second half.

What happened was that defensively less adept player, Alli, failed to help out hi full back leaving Moses with a lot of free space to exploit. Eventually this hurt Tottenham and completely turned the game. Quarter of an hour before the end Pochettino changed Heung Min and Alli, two players that significantly changed their positioning in the second half admitting the mistake. After bringing Jansen in last 10 minutes Tottenham went for 4-4-2 or, more 4-2-4 but couldn’t do much against disciplined defence.
To conclude, Tottenham had Chelsea on the ropes. However, Pochettino wasn’t satisfied with only one surprise and wanted to catch Chelsea on back foot again by changing his approach in second half. This, however, brought him only trouble and let the hosts off the hook. As they say, don’t fix it if it ain’t broken.
This analysis was first published at soccerspecific, a coaching education platform with the mission of creating and sharing the highest quality of coaching information in order to positively impact player development around the world.