Stop sides getting disorganised before the start of the tournament (6)
I believe the answer is:
desist
'stop' is the definition.
(desist means to stop)
'sides getting disorganised before the start of the tournament' is the wordplay.
I cannot quite understand how this works, but
an anagram of 'sides' is 'desis' which is present in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for desist that I've seen before include "Leave off (doing a thing)" , "Stop (doing something)" , "Stop, don't continue" , "Stop, whoa, give over" , "Cease; abstain" .)