A legacy with a B grade candidate will get in. It’s a boost, not a tie breaker.

Possible! But my previous answer was based on the "If they are so qualified" scenario. The important takeaway is that the legacy special track has a reason to exist whether or not they let unqualified students in.

So does that mean that on average, “legacy” students at these schools are lower performers? Since their bar for admission would be that much lower?

This system doesn’t really exist in Canada so I’m finding it very interesting

In the US, legacy and a building donation overlook many inadequacies.