From barely having a fit centre-back pairing to play, Tottenham Hotspur might be trying to build one of the most versatile backlines in the Premier League under Roberto De Zerbi.Clearly, one of the highest priorities on the Tottenham transfer list was significant reinforcements in the defence department, particularly at centre-back.Marcos Senesi arrived from Bournemouth on a free transfer, and Spurs have also agreed a £52m deal to sign Brighton’s Jan Paul van Hecke.With the number of centre-backs as well as the different profiles potentially at Roberto De Zerbi’s disposal, some suggest that the Italian might be gearing up to start implementing a back three system. We can take a look at Tottenham’s current squad situation, De Zerbi’s record with a back three, and his comments about choosing a formation at Spurs, to see if there’s any truth to these rumours.But first, let’s talk about back three systems and how Roberto De Zerbi used them during his career.Credit: @thefrederikkejensen / InstagramWill Roberto De Zerbi bring a back-three to Tottenham from Marseille?In the simplest of terms, a back three system involves using a back line of three players, usually centre-backs, as the basis of your on-pitch structure. This is in opposition, of course, to a back four system where the defensive line is made up of 2 centre-backs and 2 fullbacks.During his Brighton days, De Zerbi admitted that he prefers using a back four and considers himself a back four manager. He never utilised the system before arriving at his previous job with Marseille.It was at Marseille that De Zerbi started experimenting with a back three, possibly because of the players available to him, and over time, it became something he would implement more usually in games.In possession, the defensive structure would shift to create a back three of Emerson, Balerdi, and Pavard, with Weah and Paixao providing width as wingbacks, as we can see from Marseille’s Champions League game from February this year.Interestingly, De Zerbi didn’t use the back three to make his team more effective when defending.Out of possession, his Marseille would actually defend as a back four unit, only using the back three to create a favourable situation when attacking, with Weah shifting back into the back four by taking the place of a right back.By using a back three exclusively during the buildup phase, De Zerbi could have more of his players occupy and control more of the central spaces, thus giving his players more options to progress the ball through the middle of the pitch. The 3-2 formation, formed by the three centre-backs and two pivot players in midfield, was quite narrowly spaced and thus formed a more cohesive shape to invite the opposition press, showing the classical De Zerbi approach of inviting the opposition press to create spaces within the opposition structure to progress the ball and attack.The back three structure he used at Marseille could actually be seen as one of the most radical incarnations of those principles. De Zerbi was actually so intent on creating favourable conditions for ball progression through lines of pressure that he would have his goalkeeper form a part of the back three.Here we see Marseille’s goalkeeper, Rulli, doing the classic De Zerbi move of placing his studs on the ball to invite the pressure from the Newcastle players. In this situation, Rulli is the most advanced part of the back three.This, of course, is meant to free up yet another player to overload the central spaces and facilitate buildup through lines of pressure by offering the players easier solutions to find the spare man and progress the ball, and the opposition a very difficult time marking and blocking passes.Given the in-possession advantages that this iteration of a back-three system offers, could De Zerbi start implementing it at Tottenham?Is Spurs’ squad suited to playing a back-three, and if so, how would it look?To get back to the point in question, De Zerbi could indeed be tempted to play a back three system, given the plethora of choices he might have at centre-back next season.If indeed Jan Paul van Hecke completes his move to Tottenham, in Marcos Senesi, van Hecke, and van de Ven, Spurs could have three starting quality centrebacks, all confident and comfortable in playing out from the back.Given the uncertainty around Luka Vuskovic, it is not inconceivable either, that the young Croat stays at Spurs for the season, adding to the list of exceptional centre-backs available.So, how could a Tottenham back three look?First, to get the out-of-possession shape out of the way, Micky van de Ven would shift to the left back position to cover the space on the wide left, while Porro would take his usual space at right back. This setup is quite efficient defensively, as when the team transitions from in-possession to out-of-possession or vice versa, no single player is forced to take up a position they are not suited to. Spurs potential out of posession shape with a back-fourIn possession, the structure would shift to include all three of van de Ven, Marcos Senesi, and van Hecke. Spurs potential in-possession setup.Van de Ven is allowed to take up his best position at left centre-back, allowing him to make use of his aggressive carrying ability. Marcos Senesi, in the centre of the back-three, could use his passing to unlock both sides of the pitch, also leaving space for van Hecke as the right centre-back.This would allow Pedro Porro the option to fully invert into midfield, an area of the pitch he’s incredibly well-suited to, thanks to his great short and long passing range. De Zerbi has often relied on Pedro Porro to help with ball progression, and his technicality could be well utilised there.Savinho, another potential Spurs signing, and Kudus could take up the wide spaces to stretch the play, be the outlets for the midfield players, while also being put in situations preferable for them. Both Savinho and Kudus thrive in 1v1 situations and when running into space. There are, of course, a lot of other ways in which a Spurs back three could shape up.In games where defensive stability is required, a versatile player like Archie Gray could either drop into the backline or push up and form a part of the midfield, with Udogie and Porro playing the roles of more traditional wingbacks.Tottenham situational back three with Archie GrayIf Roberto De Zerbi expects a game where Spurs could play a bit riskier, their goalkeeper, someone with good passing like Antonin Kinsky, could take up the space in the middle of the back three, allowing either a fullback to invert or someone like Joao Palhinha or Archie Gray to shift between centreback positions and the midfield to be that extra passing option.The drawbacks of Spurs using a back-threeThere are also consequences and tactical weaknesses to using a back three this way, especially in transitional moments. If we go back to the first proposed back three system, we see that, with all the empty space they would be leaving, how vulnerable Spurs would be on the flanks if they were to lose possession there.Actually, following the exact bit of buildup we analysed from Marseille, when the keeper stepped up to a position alongside the centre-backs, a poor pass into the right flank led to a turnover in that area, which Newcastle were able to immediately capitalise on by scoring a goal.Still, as De Zerbi admitted in the interview the club published with the announcement of the Senesi signing, he prefers to have players who give him flexibility tactically, and in formation. The back-three could be a crucial tool for Roberto De Zerbi as he looks to take his footballing ideas to the next level. READ MORE: Tottenham have three options open to them as Luka Vuskovic agrees terms with BrightonThe post Understanding how Roberto De Zerbi could build a back-three legacy at Tottenham appeared first on Spurs Web.