So something I'm struggling with in the whole conversation around formation: does it make the most sense to use average position to decide what the formation was? I mean, we all understand that the vast majority of the time, the shape is different between attacking and defensive phases, so is there an average position in possession vs out of possession?
Specifically, there was a lot of head banging on a wall regarding 433 vs 4231, what people mean/understand by those, what it actually is, etc. deFacto is adamant that we never played 433. And based on some of those average position charts, you can see the 4231 shape for sure.
That said, if Mane, Firmino, and Salah are our attackers tasked with getting in the box and scoring, just because two of them drop more to support in the defensive phase, or even during build-up, does that negate that they are attackers? And if you have two 6's playing with a 10 in front of them as a midfield triangle of sorts, just because that 10 pushes forward more regularly than the two 6's, does that negate they are part of a midfield? These things would be much clearer if there was an in-possession chart and an out-of-possession chart. Without that, let's look at the first two examples shared earlier:
The West Ham chart shows Can and Gini back; Mane, Bobby, and Ox in a line ahead of them; and Salah slightly ahead of them. If Mane and Bobby were only slightly behind Salah because they dropped more frequently when defending, and Ox is only showing as in-line with them because he joined the attacks more often, then this chart doesn't show them in a 4231. Because they were in those spaces at different times, not lined up like that. For me, the eye test would say that Ox was clearly playing deeper than the 'front 3' last season, but I haven't watched this or any other games back recently, and this wasn't something I was keeping an eye out for either.
The Newcastle chart looks quite similar to the West Ham one. Hendo furthest back with Gini slightly ahead of him; Coutinho slightly behind Mane and Salah who are in-line with each other; and Sturridge slightly ahead of those two. So in this instance, if they've lined up the way they have because Mane and Salah dropped more frequently than Sturridge, and Coutinho starting from a deeper position, pushed forward to the edge of or into the box more frequently, then again, we would not be seeing the team line up with Coutinho next to Mane and Salah, rather, that they occupied a similar space in the middle third, but at different times.
I don't really know, like I said, I haven't watched these games back, and I haven't been trained by a Dutch coaching academy. I do find it strange though that conversation would be shut down because of a different label. "It's not a 433, it's a 4231, but here's a response to the actual thing you were talking about..." would be one thing. "You're wrong and I have nothing more to say..." may as well stay home really...
It all comes down to the principles of attack and defence, and for team shape, defence more than attack
The principles of attack are (generally - there some slight federation/coaching school differences):
Penetration
Depth
Width
Mobility
Surprise/Counterattack
Penetration is the objective. There are three ways to penetrate - shooting, passing forward, or dribbling/attacking space with the ball. If penetration at the ball is not possible, then you need depth. Depth is usually created (and by "usually", I mean almost always has been), by the striker playing on the shoulder of the last defender, and traditionally by the sweeper, but with the advent of zonal defending and sweeper-keepers, that role has been taken up by the man in the nets. The next principle is Width, which can come from either the fullbacks and wingers, wingbacks, wingers only, fullbacks only, or a combination of winger and fullback on opposite sides. The purpose of width is to open up the middle of the field. The next principle is Mobility, which is basically players leaving their position and moving diagonally in and out of the field, or else players overlapping from front to back. The last main principle of attack is Surprise/Counter-attack, which is self-explanatory - using speed to transition from defence to attack to catch a defence in a disorganised state.
The defensive principles, then, are:
Pressure/Contain - slowing down the penetration attempts at the ball. This is ALWAYS performed by the nearest defender to the ball when it is lost
Cover - this covers the attacking players attempting to create depth
Balance - Covering players who are attempting to create width, also, creating the offside line
Compactness - keeping spaces between defenders tight vertically and horizontally to reduce the effects of mobility
Consolidation - dropping back to the penalty area in a compact shape to reduce the danger of a counter-attack.
So in graphic terms, a team-shape in attack should follow the lines below:
Defensively, the lines of movement would ultimately look like this:
If you could create a Venn diagram of the overlapping principles of attack and defence, you would basically get the word "Shape", because both your attacking and your defensive shape have to be closely linked in order to make transition from one to another phase as economic as possible. This is partly why man-to-man marking was overcome by zonal defending, because zonal defending gives you a better shape to transition in both directions without losing shape.
So what about formations?
Formations let you place players in optimal positions to effect the principles of attack and defence as best as possible. For example, in a true 4-3-3, the attacking depth is handled by the #9, the width by the #7 and #11 (wingers), defensive depth by the central defenders, defensive mid and keeper, and mobility by the fullbacks, the #8 and the #10:
In a 4-4-2, there's one less player for mobility in midfield, but there is better defensive depth in the square base (as Houllier once called it on a coaching course) of the 4, 5, 6 and 8.
In 5-back systems, the roles are almost more explicit, as the central defender becomes the defensive depth, the wingbacks supply the width, the striker provides attacking depth, and the midfield 3 (either a 1-2 or a 2-1) provide the mobility as well as the defensive overloads providing a great springboard for Surprise/Counterattack.
So when we're saying things like "we don't really play a 4-3-3", it's important to make that statement, because it allows us to talk about the roles the players are actually playing, so we don't get into a situation of measuring them up against roles they aren't actually playing. For example, saying that Firmino doesn't score enough goals would be unfair to him, as he's been playing the role of the #10, which means he doesn't get into as many goalscoring positions as often as, say, Salah would. Similarly, calling Salah a "winger" belies the fact that he is our "outball", even if he starts off to the side rather than purely central. These anomalies allow us to see what Klopp is actually doing, and it's better to talk about what's actually happening in the system and formation, than it is to superimpose a "symmetrical", "media" view of the system and formation and forget the jobs the players are actually being asked to do. That's why we drill down, so that we don't look at players and the jobs they do from the wrong perspective, and then we can actually appreciate the jobs they ARE doing, rather than, say, expecting Alonso to be winning tackles, and Mascherano to be spraying the ball onto the toes of the attackers. 4-4-2, 4-3-3 etc, are okay for shorthand, but you could have 10 teams playing a 4-4-2, and all 10 would be playing it a different way. That's why precision is important.