Hi, if BTN open 2.5x, and SB , BB calls.

The flop is KJTr, SB-BB check check, then if BTN would only use one cbet on the flop, should he use one big size or one small size ??

I think it's difficult because of course BTN has the nut advantage with AQ, Q9, KK JJ TT, but there are two players who will have Q9 a considerable amount of the time, and BTN also have an advantage at AK AA KQ KJ KT, but betting small will not accomplish much in protection. But I think betting big will isolate us too much vs. Q9. But I think we want to try making weaker Jx Tx indifferent to call, for not being called too often by Q9 KJ KT.