Prague colleague reported decisive position on board (9)
I believe the answer is:
checkmate
'reported decisive position on board' is the definition.
I can't judge whether this defines the answer.
'prague colleague' is the wordplay.
'prague' becomes 'check' (I can't explain this - if you can you should believe this answer much more).
'colleague' becomes 'mate' (I've seen this in another clue).
'check'+'mate'='CHECKMATE'
Can you help me to learn more?
(Other definitions for checkmate that I've seen before include "Last call in chess" , "you lose!" , "The final killer move in chess" , "Winning call on board" , "ending on board" .)