Plan that makes a surprise start to a rough game (9)

I believe the answer is:

stratagem

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'plan' is the definition.
(stratagem is a kind of plan)

'a surprise start to a rough game' is the wordplay.
'start' indicates taking the first letters.
'to' becomes 'trat' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'a rough' indicates an anagram (a rough or broken ordering of the letters).
The first letter of 'surprise' is 's'.
'game' with letters rearranged gives 'agem'.
's'+'trat'+'agem'='STRATAGEM'

'that makes' acts as a link.

Can you help me to learn more?

(Other definitions for stratagem that I've seen before include "Plan to deceive enemy" , "Start game with cunning plan" , "Devious ploy" , "Crafty manoeuvre" , "Clever scheme" .)

I've seen this clue in the Evening Standard.

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