By Kelvin YapFollow @@plevyakin
Andre Villas-Boas started both Jermain Defoe and Emmanuel Adebayor together for the first time this season, playing a 4-4-2 formation with Tom Huddlestone and Sandro holding the midfield. Steven Caulker's injury from international duty meant that Jan Vertonghen was deployed in the middle along with William Gallas while Kyle Naughton took the left-back position that Vertonghen usually occupies.
Wojciech Szczesny made his return from injury to take his place in goal for Arsenal with a familiar back line in front of him - Thomas Vermaelen and Bacary Sagna played outside of Laurent Koscielny and Per Mertesacker.
Arsene Wenger appeared to have found his preferred side with a central midfield trio of Mikel Arteta, Jack Wilshere and Santi Cazorla, Lukas Podolski out left and Theo Walcott on the right wing, leaving Olivier Giroud to lead the line.
Spurs' high line/ front two
Adebayor played a little behind Defoe in the front two, which meant that he dropped off to collect the ball and hold up play to bring more team-mates into the area. He was especially efficient when he dropped deep because the Arsenal players picking him up couldn't handle him physically. The ones who could do so - Koscielny, Mertesacker and Vermaelen - needed to stay behind to hold the defensive line.
He still played as a striker, though, which meant that he stayed up front mostly and didn't track back into midfield as much as an attacking midfielder like Dempsey or Sigurdsson would.
It's also interesting to observe that Tottenham's two strikers went up against defenders who contrasted their strengths. Defoe, who is speedy but lacked the physical power, went up against Mertesacker, who is physical but is easily beaten for pace. Adebayor, who is physical and not as speedy as Defoe, went up against Koscielny, who is faster but not as physical as Mertesacker.
With Sandro and Huddlestone holding the midfield, it left a huge gap between them and the strikers when Arsenal had the ball, effectively surrendering space around Arteta's area in shallow midfield.
Villas-Boas countered this by introducing the high defensive line - the very same one that got him into trouble back when he was in charge at Chelsea. It was a risky move, but it paid off because Arteta was averse to launching cross-field passes, which meant that Spurs had more chances of cutting the ball out on the ground simply because they had players in the same area.
In the end, this led to Spurs directing their attack down the channels on the flanks while Arsenal preferred to play down the middle to relieve the pressure and take time to build up their attack.
Tottenham's opening goal showed this - the high line enabled Vertonghen pushed up to send the ball - which was originally meant to be for Bale cutting in from the left - behind the Arsenal defence. Instead, Defoe showed great speed to turn Mertesacker out and create the chance that led to Adebayor's goal.
Adebayor's ruinous red card
The match was starting to shape up into an intriguing battle - Spurs were getting the ball upfield more efficiently because of their physical midfield literally pushing their way up while Arsenal started to get their act together and found the correct combinations down the flank.
However, Adebayor's rash and needless challenge on Cazorla got him sent off and sabotaged his team.
Without their regular outlet to hold the ball up and relieve the pressure, Spurs succumbed to sitting back and couldn't play out of their own half. It was from this pressure rather than a specific tactical strategy that helped Arsenal score three goals in the half.
Arsenal's inverted triangle
Credit must still be given for Wenger for introducing a more direct approach to Arsenal.
He has previously asked Cazorla and Wilshere to play in deep roles to try and build up play from there but it only led to Arsenal passing the ball around without creating a threat on goal.
This time, he switched things around by having only one holding midfielder in Arteta instead of having Wilshere partner him, making Arsenal's formation a 4-1-4-1 - much like the recent Manchester United that featured Wayne Rooney in midfield beside Tom Cleverley. It denied Arteta the option to pass the ball sideways, forcing him to build up play faster into the Spurs half to keep them under pressure.
This was also possible due to Tottenham's flat midfield which had to occupy themselves with their attacking midfielders instead of pushing on to pressure Arteta.
Because of the space behind the high defensive line, it was only natural that Arsenal directed their play towards their right flank, where they could make use of Walcott's speed to run at Naughton, who was the weakest link in the Tottenham defence and a natural choice for them to exploit. Mertesacker's goal came from the area and Giroud forced Lloris into two excellent saves after crosses from that flank.
AVB sticks to his principles
Villas-Boas became the fourth manager in the league to use a three-man defence this season when he brought on Clint Dempsey for Walker and Michael Dawson for Naughton at half time.
The move came when Spurs still had Lennon, Defoe, Bale and Walker in their side. Logically speaking, most managers would have sat back and sprung the counter-attack for goals using their speed on the break against the slower marginally slower (imagine Bale sprinting at Mertesacker!) Arsenal defence but Villas-Boas chose to play ‘proper' football instead.
The switch to a 3-4-1-1 formation allowed Spurs to play like they normally do up front since it's very similar to their usual 4-2-3-1; the only difference was that their wingers came in from a deeper position and they had no full backs to overlap. This gave them a sense of familiarity as to who or where to play the ball to, which helped them move the ball up front to relieve the pressure from Arsenal that they had been under towards the end of the first half.
The down side of it was that Arsenal could easily play through balls down the flanks to drag the back three out of shape since they didn't get much help from their wingers. Although Dawson did cut out a few of the through balls floated in to Walcott, Arsenal managed to break through in that manner for Cazorla's goal.
In the end, Tottenham managed to pull a goal back via Bale. Again, it wasn't due to any particular piece of strategy but more of brilliance from Bale and a bit of naive defending from Mertesacker, who assumed that Bale would never use his right leg to shoot and showed him the inside of goal from the left flank. The Welshman did fire with his weaker foot and the ball sneaked in between Koscielny's legs into the goal.
Wenger's belated reaction
The obvious solution for Wenger to counter Villas-Boas' switch was to bring on more wingers to set up two-on-one situations on the flanks sinceTottenham's wingers were too far up the pitch to cover for their defenders.
Alex Oxlade-Chamberlain and Andre Santos were shown to start warming up minutes after half-time in reaction to Tottenham's changes but the duo only made their appearances in the final ten minutes.
The change proved to be an effective one as Arsenal immediately enjoyed a spell of possession when Santos came on to put Tottenham under pressure again. The dominance eventually told against an exhausted Tottenham side when Oxlade-Chamberlain stole the ball from the defence to set up Walcott's goal late in the game.
Overall, it was shaping up to be an excellent derby until Adebayor's moment of madness. However, Villas-Boas' changes kept things interesting by making changes.
Villas-Boas deserved more credit than the scoreline suggests. The decision to start both Adebayor and Defoe looked to have paid off and Spurs had a decent chance of winning the match before Adebayor's antics sabotaged the match.
The Portuguese showed further bravery and intelligence to switch to a back three at half time in an attempt to salvage the situation instead of doing damage limitation many other managers would have done.
As for Arsenal, the more direct approach due to the inverted triangle midfield is an improvement from the previously-insipid midfield which proved to be effective against a flat four midfield. In this, Wenger may have discovered a potent weapon to use against most Premier League sides which utilise a 4-4-2 formation.
Wojciech Szczesny - 6
Bacary Sagna - 7.5; Per Mertesacker - 7 ; Laurent Koscielny - 7.5; Thomas Vermaelen - 7.5
Mikel Arteta - 8.5; Jack Wilshere - 8; Lukas Podolski - 7.5; Santi Cazorla - 8.5; Theo Walcott - 7
Olivier Giroud - 8
Aaron Ramsey - 6.5; Alex Oxlade-Chamberlain - 7; Andre Santos - 6.5
Hugo Lloris - 8
Kyle Walker - 7; William Gallas - 5.5; Jan Vertonghen - 7.5; Kyle Naughton - 4
Aaron Lennon - 7; Tom Huddlestone - 7; Sandro - 6.5; Gareth Bale - 8
Jermain Defoe - 6.5; Emmanuel Adebayor - 3.5
Michael Dawson - 7; Clint Dempsey - 6; Tom Carroll - 6
Kelvin will be analysing a Premier League match every Monday in Tactics Watch. You can reach him by following his twitter account @plevyakin for more tactical insights and football updates.