in what was a very brave

[Maybo]

Mac Allister had a good game as their holding midfielder against Chelsea, in what was a very brave and attack-minded set-up by Jurgen Klopp.
(Moises Caicedo: Why Chelsea and Liverpool both wanted Brighton midfielder by Danny Murphy)

What's the difference if I say "Mac Allister had a good game as their holding midfielder against Chelsea, in a very brave and attack-minded set-up by Jurgen Klopp"?

 

[jutfrank]

The difference is it's not quite as good.

 

[Maybo]

The difference is it's not quite as good.

What's the difference in meaning?

 

[jutfrank]

Let me try to explain this simply.

Mac Allister had a good game as their holding midfielder against Chelsea, in what was a very brave and attack-minded set-up

The red part tells the reader that the writer is going to describe the formation.
The blue part describes the formation.

 

[Maybo]

Why is the red part needed to tells the reader that the writer is going to describe the formation?

Why does the writer need to tell readers he’s going to tell the formation instead of just tell it directly to readers?

 

[jutfrank]

Why is the red part needed to tells the reader that the writer is going to describe the formation?

Why does the writer need to tell readers he’s going to tell the formation instead of just tell it directly to readers?

Don't think about what is 'needed'. Think about how the speaker makes her message understood as effectively as possible.

 

[Maybo]

Don't think about what is 'needed'. Think about how the speaker makes her message understood as effectively as possible.

But I don’t understand the difference in meaning so I can’t understand how the speaker make her message understood effectively by using “in what was”.

 

[jutfrank]

There's no difference in meaning. It's just a way to say it better.

 

[Piscean]

Adding the underlined words in in what was a very brave and attack-minded set-up gives more prominence to the remainder of the clause.