British team in game goes downhill? It’s the quantities of beer (8)

I believe the answer is:

brewskis

'the quantities of beer' is the definition.

'british team in game goes downhill?' is the wordplay.
'british' becomes 'br'.
'team in game' becomes 'ew' (East and West are a team in bridge).
'goes downhill?' becomes 'skis'.
'br'+'ew'+'skis'='BREWSKIS'

'it's' acts as a link.

I've seen this clue in The Independent.

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