Towards the effect of the decoding depth set {2,3,4,5}, our multi-pass decoders obtain the approximate results, but the whole curve of BLEU is on an upward trend.
the multi-pass decoder with decoding depth 5 achieves the best performance with 38.64 BLEU, while the one with decoding depth 3 performs the worst among the decoding depth set with 38.55 BLEU.