Restricting manager experience in a league

It would be nice to have new players be able to create an open league but have other players join who also have limited experience.

You can actually do that, but unfortunately there's no way to enforce it. For example, you could create a league, and specify in the description that only rookies and prospects are allowed... but if an experienced player wants to be a jerk and join up, I don't think there's any way to stop him.
I'd love to see some leagues like you mention. There's a steep learning curve in this game-- no matter how much you know about baseball-- and if newbies get consistently clobbered by the veteran players, they might lose interest and give up on the game entirely. And that's a bummer.

You can actually do that, but unfortunately there's no way to enforce it. For example, you could create a league, and specify in the description that only rookies and prospects are allowed... but if an experienced player wants to be a jerk and join up, I don't think there's any way to stop him.
I'd love to see some leagues like you mention. There's a steep learning curve in this game-- no matter how much you know about baseball-- and if newbies get consistently clobbered by the veteran players, they might lose interest and give up on the game entirely. And that's a bummer.

When I first started playing here, there was a league created called a Ring Fling, the description stated it was for newer players who had yet to win a ring. That way, one newer player was guaranteed to win a championship, playing against other relative newbies. That's where I won my first championship! When you won a ring, you had to drop out of the group and try to fill that last spot again....
You could advertise for 12 new managers who have yet to win a ring and try to fill one that way.

I think that's a great idea. Good luck, appb1, if you decide to do it.

The 1st team I played on-line--I did exactly that.

I created a league and asked for rookie or low experience guys--for the most part that happened, but two very experienced guys joined that league, both wound up in my division---one of them dominated the league easily, taking the ring, the other had a more than +70 run differential over my team but had bad luck and finished 3rd. I did manage an 82-80 record.

I couldn't get away from that guy all year--he joined 50% of the leagues I was in and usually was in my division, finally I finished ahead of him the last league of that season (I just drafted all his players)

In a way I'm glad it happened that way--I wouldn't have learned much in an all-rookie league.

Most people just see an auto league and join it, never bothering to look at the header notes of the league.

I think it is easier on rookies the last few seasons--rule changes have stymied a lot of the strategy of building a pitching staff--and everybody spends the same money--all you have to learn now (for the most part) is the dynamics of the park you chose and the players you put in that park.

Can't you password private leagues?

You can. When you create a league you are given a 5 letter PW to share. For a restricted situation like appb1 is after, the league would then need to be advertised on the boards and the PW shared via PM to those who sign up.