Where all eyes are focused when the chess tournament is in motion (2,3,4)
I believe the answer is:
on the move
'in motion' is the definition.
(thesaurus)
'where all eyes are focused when the chess tournament' is the wordplay.
I cannot quite see how this works, but
'when' could be 'on' (I've seen this in other clues) and 'on' is found in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
This explanation may well be incorrect...
'is' acts as a link.
Can you help me to learn more?
(Another definition for on the move that I've seen is " Travelling".)