I've always been interested in how coaches handle this aspect of a scouting report when guarding a great shooter - the idea that you need to lock-and-trail, or get on his outside hip to be able to chase the shooter over every screen. By itself I understand the concept, and I get why you want to do it on a great shooter. If all you have to worry about is the great shooter and not letting him get any open looks, it makes sense. But how do you handle helpside situations when you lock-and-trail on a shooter?
If you want your defender to stay on a shooter's hip, you can't ask him to get in any sort of helpside position. Regardless of where you want your help to be, he can't realistically get into a help position, away from his man, and then return to his man to get on his hip to beat the screen. You are giving up one or the other. But I constantly see coaches who ask their kids to do just that, or at least don't really explain how to handle helpside when someone is locked in on a shooter.
We've played against a number of teams that will "no-catch" one of our shooters and just won't leave him. We actually won an NCAA Tournament game a few years ago where our best shooter didn't score a point because our opponent face-guarded him the entire game. And to play him as an individual, it was the right way to shut him down. But we just sat him in the opposite corner away from the ball with his man all over him, and ran our offense. We had a great post player who we isolated on the block and we were able to throw him the ball over the top without help, and our dribble penetration was very effective because we could usually get all the way to the rim with no help. They took away our shooter, but their team defense suffered big time and we had no trouble scoring.
I'm not saying the philosophy is a bad one, I'm just not sure many coaches think about the effect it has on the rest of the defense. If you have any sort of helpside principles at all, they are going to be compromised by one guy locked onto the hip of a shooter at all times. You can't tell me he can get into helpside and still get back to his shooters hip when the down-screen comes. Just think about a post-up, staggered away set, or a simple cross-screen, down-screen set. There really isn't a way to do both. If the shooter is setting the cross-screen and then coming off the down-screen, you either can't help on the cross-screen or you can't get back to his hip for the down-screen. It's just not possible.
I think one of the mistakes we make as coaches is being ambiguous with our kids about certain situations. We don't really define them and just react based on the result. And this is one of those situations I see most often. You tell a kid not to leave a shooter and stay on his hip to beat screens, but you don't really address the helpside situation with your team. And that creates some confusion and uncertainty.
Staying on the hip of a shooter at all times can be an effective strategy. But think about what it might do to the rest of your defense, and how you can address that. There are decisions you can make to sort it out, but by not making those decisions you are putting your team in a bad position.