Game ends in supposed deadlock - immediately son beats me (3,5)

I believe the answer is:

god knows

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'beats me' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'game ends in supposed deadlock immediately son' is the wordplay.
'game' becomes 'go' (go is a board game).
'ends in' says to take the final letters.
'immediately' becomes 'now' (I've seen this before).
'son' becomes 's' (genealogical abbreviation for son).
The last letters of 'supposed deadlock' are 'dk'.
'go'+'dk'+'now'+'s'='GOD KNOWS'

Can you help me to learn more?

I've seen this clue in The Independent.

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