that's the tail shouldn't go up but you have a very long tail of words right and what you want to do is in this case you want to sample these words here more but they are they appear so much more often than if you simply sample according to their unigram distribution you basically not regard these words right here you'll forget about them and your performance will suffer because they do appear every now and then so what you want to do is you want to push the dose down a little bit and the optimal amount for the