Multi-way NMT systems in both directions improved translation quality (by 3.09 -5.28 BLEU points for Russian→Estonian and 2.16 -4.31 BLEU points for Estonian→Russian) for all three model architectures (deep GRU, convolutional, and transformer), for which we performed multi-way experiments.
the results showed that the most stable architecture for multiway model training was the deep GRU model architecture.