Is Shards a good solution to implement a Multi-Tenant architecture?

I'm using Spring3/Hibernate and trying to build a fun little web-based game. A user first logs into the web app and it shows them their saved games or allows them to create a new game. From there it launches them into their game.

I was thinking about having a "master" database that would have all the user accounts and a list of their saved games. Each game would have it's own database since they are very independent, however each game database is the same schema. I thought this might be a good way to separate the data, increase performance, and allow me to backup games individually, etc. These game databases can get very large so I thought separating them would increase performance. A user is only connected to 1 game at a time.

Is this a good design pattern? Is shards the way to implement this? Any help would be appreciated! Thanks!

Yes, I think that it is.

But it's making me wonder what would be of Shards with the multi-tenancy new feature in Hibernate 4.

https://community.jboss.org/wiki/Multi-tenancyDesign?_sscc=t

Forget. As a matter of fact, Shards seems to be the exact oposite to the multi-tenancy feature.