watch attentively and see only a third

I want to raise a phrase which Iab Hui has said

mag8ging2 tion2 san1 sian5

目緊睇三成｜目紧睇三成

Watch attentively (and) see a third

Mandarin subtitles: 盯緊才能瞧見三分｜盯紧才能瞧见三分

watch attentively (then one) can have the capacity to see to some degree

Do note that Iab Hui is fluent in English and the English subtitles wrote “keep an eye on it to see 30%” and this means the Mandarin translation does not tie in what is said in Teochew.