OpenBracket at WMT 2026: COMET-MBR System Combination over Arabic-Native and Multilingual Models for Low-Resource Arabic-English Translation

Abrar Alotaibi


Abstract
OpenBracket submits constrained systems to both English-paired directions of the WMT 2026 Low-Resource Arabic-Asian Language Translation task, trained on the official data only (21,000 pairs) from publicly available checkpoints. Per direction we submit a primary COMET-22 MBR system combination over five fine-tuned models (NLLB-3.3B, two X-ALMA variants, ALLaM-7B, OPUS-MT) plus two contrastive systems: an ALLaM-7B fine-tune and sampling-based MBR over NLLB-3.3B. On the official test set, our primary ranks first among all teams in Arabic-to-English (BLEU 33.83, chrF 59.72, TER 57.00, COMET 82.49), and in English-to-Arabic it attains the highest COMET on the primary leaderboard (BLEU 21.81, chrF 54.99, TER 69.29, COMET 85.23).
Anthology ID:
2026.wmt-main.167
Volume:
Proceedings of the Eleventh Conference on Machine Translation
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Barry Haddow, Tom Kocmi, Philipp Koehn, Christof Monz
Venues:
WMT | WS
SIG:
SIGMT
Publisher:
Association for Computational Linguistics
Note:
Pages:
2266–2272
Language:
URL:
https://aclanthology.org/2026.wmt-main.167/
DOI:
Bibkey:
Cite (ACL):
Abrar Alotaibi. 2026. OpenBracket at WMT 2026: COMET-MBR System Combination over Arabic-Native and Multilingual Models for Low-Resource Arabic-English Translation. In Proceedings of the Eleventh Conference on Machine Translation, pages 2266–2272, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
OpenBracket at WMT 2026: COMET-MBR System Combination over Arabic-Native and Multilingual Models for Low-Resource Arabic-English Translation (Alotaibi, WMT 2026)
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PDF:
https://aclanthology.org/2026.wmt-main.167.pdf