Boxing out, emphasis on the second word. That was one of the mantras I obsessed about in every practice I ever ran for a girls high school program for about 30 years, and that was the primary defensive failure in our loss to Villanova. Yes, having Liv on the floor would have helped, but we did have enough bodies on the floor to have cut Villanova's offensive rebounds by 50% to 70% had we boxed out! Which means putting a body on every opponent immediately when a shot goes up, putting a body between that opponent and the ball wherever the ball goes and however far from the basket you are. Only that disciplined reaction allows the defender to control the maximum floor area and the maximum chance to get to the ball first. And it's not a matter of height!!!
Yes, there were some problems avoiding screens set by Villanova to get open 3's, especially earlier in the game, but we reduced those errors late on. But the failure to box out was a gift to Villanova and an invitation to get more shot opportunities.
Why did we not box out properly? Physical laziness? Most often not. But we did not discipline ourselves to— always first— find the closest opponent and put a body on them, and then look for and go to the ball.
I confess, I am super obsessed with this issue, especially when I don't think this year's edition of the UConn team has, after 18 games learned to execute that particular essential basketball strategy.