The description of the Fluency Fast Track for German is “Play 19,983 sentences with 19,983 unique cloze-words in order of difficulty.” However, the clozes do not all seem to be unique. This screenshot shows two sentences with the cloze word “liebt” (and the same meaning, “loves”) not only in the same round, but one right after the other. See the bottom of the image.
And here’s another cloze word, “müde”, that appears in two Fluency Fast Track sentences (though not in the same round):
Again, the word has the same meaning in both sentences.
Also, I found three instances of “geboren”.
I find this depressing. I gave up playing the 4,000 Most Common collection because it was so much work to manually mark all the duplicates I encountered. I thought that if I played the Fluency Fast Track, I might have to spend some time at first going through familiar words, but eventually I’d get far enough into the less common range that the exercise would be worthwhile. I told myself that at least I wouldn’t have to waste my time on dealing with duplicates. But I guess I was wrong.
Any comments, @mike ?