The Thai are not 'experts.' They did not coach a man into the ATP top 20 by correcting his mistakes and using his strengths, after spending rookie years under the top one hundred. (Proof enough that dad is the best man for the job!!) There is a tendency for Asian culture to think what they currently have is not the best; for Paradorn, that if dad coaching got him to top twenty that for sure a 'real' coach will get him higher. The parent as coach has produced many number ones on the WTA (everyone except Lindsay as far as I know) so who's to say it can't work on the ATP?
for you information, the 'thai expert' who started this thought is not a real expert, he's just a commentator what is worst is that he's not even regular tennis commentator!! And we all know how rubbish the commentator always is!!!