Regarding the ten free to play champions, and Kalista's problems last week...

Last week one of the ten free to play champions was disabled for a few days as a result of Kalista having a strange bug. She's available again this week, for a total of 11 champs, so it's not much of a problem if you wanted to try her out.

While it's incredibly unlikely, The possibility exists that there could have been a game in which the tenth player would have been unable to pick a free to play champion, as all the other 9 might have been picked. I think that it might be advisable to enhance your system for determining free to play champions, so that you can temporarily add new ones on demand if something like that happens in the future.

Obviously this is something that would be ludicrously unlikely. who gets to level 30 without unlocking a single character? And I think I remember hearing someone say that you have to have a certain number of characters unlocked before you can do draft. Even if that's true, I know from my experience as a programmer that redundant systems to prevent issues are far preferable to relying on the system to never break down.

Assuming that a player had the exact number of characters unlocked to do draft, they'd literally have to purchase a new one just to do draft last week, assuming one of them was Kalista.

It might help to have a champion list for each champion called "Closest matches" that showed characters similar to that champion.

For example, Kalista's closest matches would be Vayne, Lucian, and maybe Teemo. (I admit I haven't played all ADC's, but these have mobility) In the event that Kalista had another game breaking bug, you could simply look up the nearest match and enable that champ for free to play week. You might even share the list on the champion page (though that would start to get cluttered), so that players who like Kalista know a few other champs they might like.