Duke playing its A game will not lose to St John's. Duke playing its B game could lose to SJU.
SJU is fast, tough, and they don't give up. They're audacious- that's the main trait I took away from watching them this year. I don't think UConn was ready for that audacity the first time they played them. The Johnnies had a game plan, and they stuck to it. The second time around, UConn was as pissed and intense as they'd been in a while and just eviscerated them.
SJU has no answer whatsoever for Elizabeth Williams, but if their guards have a good game, they could give Chelsea Gray problems.
Duke is a lot more talented than SJU and a lot less tough. That's why I say A game vs A game, Duke wins this. But if SJU takes Duke out of its A game, it could be a grind.