Best position to make a dramatic observation? (3,4)

I believe the answer is:

box seat

I'm a little stuck... Click here to teach me more about this clue!

'make a dramatic observation?' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.

'best position' is the wordplay.
'best' becomes 'box' (I can't explain this - if you can you should believe this answer much more).
'position' becomes 'seat' (seating is a kind of positioning).
'box'+'seat'='BOX-SEAT'

'to' is the link.

Can you help me to learn more?

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app