The 7 bag is a type of randomizer for Tetris that guarantees you'll get 1 of each piece every 7 pieces. Essentially, what it does is it puts all of the 7 tetriminos in a "bag" and draws them out on a "table" in the order in which they'll come next. Then, it puts all of the tetriminos on the "table" in the same order into the next queue. This makes it much easier to have I and other pieces which are much harder to get in the original unbiased randomizer or the Nintendo Tetris randomizer. This also makes sequences like 3 O pieces next to each other pretty much impossible. And yes, it's guaranteed that you'll get an I piece out of the 7 next pieces, which means you don't have to wait for 2 hours before finally being able to clear tetrises. This makes the game much easier, especially for stacking and T-spinning, and it's good for when you're fighting an opponent.
Feel free to use it, but with credit. Press space to remove the next piece from the queue. This project is equipped with a queue populator This particular populator refills the queue when the queue's length is equal to or less than 7, keeping the queue at a length between 10 and 14.