In Gabaibaachan, in ch. 15, at a climax in the story, the protagonist's mother finally makes an appearance and cheers him on at a running race. He calls back:
"I'm a terrible student but I'm a good runner, aren't I?"
My question is what the ば particle is doing there. It seems to replace が. Is this a common feature of Sagaben?
After reading the comments below, I realise ば can replace を in the 九州 dialect. After googling をできない, I found some examples of this collocation, even though I would have expected ができない. So, my updated question is, is the character in fact saying, 「勉強(が)をできない」?