How important is block defending in a 4231 with two CDMs?

[goku4]

So I read some articles about split block and mid block as a defence tactic. The idea seems to reduce vertical gaps in your team. However, when using a 4231 with two CDMs, do you think it is necessary to use this kind of a strategy? For instance, when I have very high LOE and standard backline, I still have two CDMs covering when the opposition gets past the pressure of my front 4. I kind of have the impression that split or block defending makes somehow sence for formations without CDMs, or am I wrong?

[NotSoSpecialOne]

Having your LOE one notch lower than defensive line makes sense (to me anyway) for vertical compactness whether your pivot is in the DM strata or CM strata, as the only thing that changes here is where the vertical space is (DM strata = between your pivot and front four, CM strata - between your CMs and defensive line). 

[Experienced Defender]

When you use a formation with 2 DMs, a lower level of vertical compactness is definitely less of a problem compared to formations with no DM. Therefore, in a 4-2DM-3-1 you can afford to be (a bit) less compact in terms of the DL-LOE distance than in a standard 4231. Which still does not mean that you should go to any kind of extreme. 

[CARRERA]

4 hours ago, goku4 said:

So I read some articles about split block and mid block as a defence tactic. The idea seems to reduce vertical gaps in your team. However, when using a 4231 with two CDMs, do you think it is necessary to use this kind of a strategy? For instance, when I have very high LOE and standard backline, I still have two CDMs covering when the opposition gets past the pressure of my front 4. I kind of have the impression that split or block defending makes somehow sence for formations without CDMs, or am I wrong?

When thinking about of how to setup your defensive block and how compact your team needs to be vertically, its not only the defensive phase that has to be taken into account. You also need to consider your teams attacking depth and its vertical relation. The reason therefore is, that you usually don't want your players to run the whole pitch up and down the full 90 minutes, which can be quite exhausting. Also there are several other factors besides purely adjusting defensive line and line of engagement which affect your teams vertical distance beween the lines.

• The Formation is key for where you team is most effective at defending and how compact they will be. As you found out already, formations with only 2 CM are not as compact as a formation utilizing one or more DM. Another example is playing with wide midfielders instead of wide attacking miedfielders, will heavily favour a more defensive approach utilizing a low block.
• Mentality has also a big effect. A more positive mentality will encourage your team to push up the pitch in both defensive and attacking phase. But your team will still push up the pitch even more in attacking phase, which affords your players to travel more meters in both directions whenever possession transitions from one team to the other. Thats why usually higher blocks do favour a more positive mentality. At least if you focus on keeping your players fresh rather than being exhausted. This vice versa counts for more defensive mentalities.
• Defensive Line does also affect both defensive and offensive phases of play as it generally makes your players to push up from the back. This might me quite handy to implement a higher defensive block or increase your vertical compactness in defensive phase. In the attacking phase it will provide additional passing options and makes it easier for your team to recycle possession which heavily favours a short passing style of play. However when it comes to a more direct attacking style, this can be quite tough, as you rather want larger gaps between your lanes, to create space for your players to receive them direct passes.
• Line of engagement will only affect your pressing line in defensive phase. It has no impact to attacking phase. It can be used determin your defensive block and your vertical compactness in defensive phase without affecting your attacking play.
• Individual Roles & Duties: I dont want to get too much into specific roles here, but you can do quite alot with simply distributing your duties. To keep it as simple as possible. While defend duties will primarily take over defensive responsibilities and remain sitting deep in all phases of the game and attack duties will primarily take over attacking responsibilities and remain pushing up in all phases of the game, support duties will take over both defensive and attacking responsibilities in all phases of a game in a fluid way. They can be perfectly used, to create link ups between the lines or create additional compactness. However they are not as efficient in carrying out those responsibilities as a defend/ attack duty would be.

So regardning your question wether to implement a vertically more  compact defensive block, I'd say: no you don't nessecarily have to in any (basic) formation. Generally spoken though, its more a matter of style and personal preference, if you are looking to balance out the weakness of your tactics, or if you are trying to play through their strength by further encourageing them. Both can lead to great success.