There are many ways of computing BLEU. Researchers may use different tokenization, byte pair encoding or raw text processing methods which will affect the final score.
sacrebleu package helps to standardize BLEU computation to make the comparison of model performance easier.
https://github.com/mjpost/sacrebleu
sacrebleu package helps to standardize BLEU computation to make the comparison of model performance easier. https://github.com/mjpost/sacrebleu