I started playing Canasta this past weekend with some of my relatives. We played with four people, two teams of two. I understand most of the strategy for the game, but freezing the pile generally seems like a terrible idea.
I noticed that, in general, the team that froze the pile wasn't the team that ended up picking it up. What it did create was large discard piles, and whoever picked it up got a lot of points that hand, along with the wild card that the other team used to freeze the pile in the first place.
In some cases, the reason a player froze the pile was to avoid discarding something that the other team had already melded, but it still seems more beneficial to dump a card on a relatively small discard pile that you know will get picked up. Plus you wouldn't be losing a wild card in the process.
I also understand that this gives you some leeway in discarding; suddenly you're able to discard cards that have been melded and are on the table since there is a low chance that the opposing team is still holding onto them.
I feel like I might be overlooking some other benefits of freezing the discard pile. When is it beneficial to freeze the discard pile? In what circumstances might this be a good play?