What went wrong with Bielsa's Leeds United?

Both managers started with their usual formation, 4231 for the home side and 4141 for Bielsa's team. This offered a 1 vs 1 almost all over the pitch, except for the central defenders who doubled the marking of the striker, the rest of the pitch was marked by individual duels.

At the start, Leeds' approach was one of vertigo and verticality, but United responded with the same formula. Therefore, the first half was an intense match, with a lot of back and forth, with United taking the lead at the start, and then a more balanced game.

But in quick attacking transitions, there was always the feeling that United's defence was better organised. Leeds' commitment to individual marking while United attacked positionally could be countered. Red Devils' onslaught, 4 goals in 16 minutes. With two key players to make it happen. Pogba, who finished with 4 assists (he became the 7th player in the history of the Premier League to do so) and the Portuguese B.Fernandes who scored 3 goals.

This string of goals marks in principle the perfect effectiveness of the home team in the second half. In the whole period, they had 5 shots and scored 4 goals.

But the reason for this was United's clever positioning to take advantage of their opponents' marking.

What went wrong for Leed's United?

Manchester United employed numerous strategies of Dismarking  

 James moved toward in with the ball putting up with Dallas with him thereby generated space behind which United peer to exploit through the run of Mctominay on the blindside of Klich. 

 It can't be interpreted  in the guise of dismarking, having said that  more of fastball circulation to find free man, Lindelof received from Maguire, it's forged problematic animation for Rodrigo to trim this much ground plus Lindelof's touch into the space forward makes it more difficult, now Struijk was a bit lofty,

cultivated a gap for Pogba to run onto and if the timing of Pogba was a bit better along with Lindelof's diagonal this could've easily been a big chance for United(United wielded finding the free Cb pattern throughout the game).

In defensive transition leed's vacate several gaps:

In this scenario, Leeds win the ball and then again lose it(which explains why Koch is positioned in the L.H.S. due to his man-marking of Bruno). With Koch in the HS and Struijk losing out to Greenwood, it gives Greenwood space, to run onto and find Pogba.

In this animation we see the shortcoming of having both the 8s high up the pitch, Leeds go long and lose the ball and with the team stretched all over the pitch, crucial gaps are opened for United to exploit. 

Limited idea/ option in the build-up:

 Leeds lacked midfielders who dropped deep to assist while Leeds were building(both the 8s were positioned high up). This is why Leeds were going long which lead to them losing position while also not winning second which was won time and time again by Fred and Mctominay.

In this animation when one of the 8s drops deep Leeds can build up play patiently in place of moving direct and losing possession which didn't do them much favour in this game.