Spaced repetition systems have gotten better

I wish Anki could dynamically adjust the new cards introduced each day, based on whether you get them right or wrong on first viewing.

Getting 10 new cards that I happen to already know is easy. That's very different than getting 10 new cards that I get wrong, and therefore need to memorize.

I'd love to have 2 settings like:

  - Max number of new card fails, say 4
  - Max number of new cards, say 20

After 4 fails on new cards, Anki would stop showing new cards for the day. But if they're all easy, I might get up to 20 new cards in a day.

Fancier versions could use a decaying average of new card fails from the last few days. Those recently memorized cards are more challenging during review.