Bad team standard is hard to explain (7,4)

I believe the answer is:

offside rule

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'hard to explain' is the definition.
I know nothing about this answer so I can't judge whether this works.

'bad team standard' is the wordplay.
'bad' becomes 'off' (eg meat that's gone off is bad).
'team' becomes 'side' (both can mean a sports team).
'standard' becomes 'rule' (synonyms).
'off'+'side'+'rule'='OFFSIDE RULE'

'is' acts as a link.

Can you help me to learn more?

I've seen this clue in The Guardian.

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