Right, since it's non-refundable, in normal situations, you can't get the full maximum credit. As
@MDM mentioned I'm pretty sure I've seen some specific examples where you could (it would have to involve something that raises tax without raising AGI), but generally not.
This is because you need an AGI under $38,500 as MFJ to get the full $2000 credit, but under normal circumstances, and assuming all of that is earned income (capital gains would increase AGI without increasing tax at that income) your total tax due would be about ($38500 AGI - $24k standard deduction) x 10% tax bracket = $1450, so that would be your max savers credit. Therefore, the trick to to balance Roth/traditional such that you're as close to $38500 AGI without going over.
Remember you can recharacterize your IRA contributions any time up until your tax filing deadline.