{"slug":"open-beam","date":"2026-10-07","channel":"ai","layout":"chart","title":"China's best open model leads the US by 46 Arena points, down from 72","dek":"The best US open model on the board is Nvidia's Nemotron 3 Ultra. Reflection's Beam, billed as the top non-Chinese open model, is not yet scored.","body":["The Decoder reports that Reflection AI's Beam, a 501B-parameter model (23B active) due under Apache 2.0 later this month, is now the strongest open-weight model built outside China. Reflection says it matches GLM 5.2 on key benchmarks. Beam is not on LMArena yet.","LMArena's text ranking shows what it has to beat. On 2 October the top open-weight model from a Chinese lab was Xiaomi's mimo-v2.6-pro at 1491, ahead of the best US open model (nvidia-nemotron-3-ultra-550b-a55b-nvfp4, 1445) by 46 points and Europe's Mistral Large 3 (1428) by 63. A year earlier the China-US gap was 72.","The gap shrank because US open models jumped (Gemma 4 in March, Nemotron 3 Ultra in July), not because China stalled; its best rose 63 points. A Beam score above about 1445 would make it the top non-Chinese open model on the board."],"facts":[{"label":"Best Chinese open model, 2 Oct 2026","value":"1491 (mimo-v2.6-pro)"},{"label":"Best US open model","value":"1445"},{"label":"China lead over US, Sep 2025 to Oct 2026","value":"72 to 46 pts"},{"label":"Best European open model (Mistral Large 3)","value":"1428"}],"chart":{"type":"line","title":"Best open-weight text score by lab country (LMArena)","unit":"Arena score","x":["2024-01-25","2024-02-15","2024-03-27","2024-04-26","2024-05-27","2024-06-29","2024-07-31","2024-08-28","2024-09-27","2024-10-28","2024-11-22","2024-12-30","2025-01-28","2025-02-27","2025-03-30","2025-04-23","2025-05-22","2025-06-24","2025-07-28","2025-08-28","2025-09-30","2025-10-17","2025-11-26","2025-12-30","2026-01-29","2026-02-26","2026-03-31","2026-04-30","2026-05-27","2026-06-25","2026-07-30","2026-08-27","2026-09-30","2026-10-02"],"series":[{"name":"China","values":[1112,1147,1148,1153,1168,1185,1187,1187,1257,1263,1263,1315,1358,1363,1370,1373,1368,1424,1426,1429,1428,1438,1442,1440,1446,1452,1449,1468,1469,1468,1473,1476,1491,1491],"hi":true},{"name":"US","values":[1106,1106,1103,1207,1202,1214,1262,1266,1266,1271,1269,1269,1269,1269,1340,1342,1339,1357,1357,1367,1356,1358,1365,1365,1366,1366,1444,1441,1442,1441,1445,1445,1445,1445]},{"name":"Europe","values":[1123,1120,1114,1147,1144,1147,1146,1250,1251,1251,1251,1251,1252,1251,1251,1251,1248,1271,1335,1341,1338,1339,1339,1433,1431,1431,1431,1430,1430,1430,1429,1428,1427,1428]},{"name":"Other","values":[1077,1083,1148,1192,1189,1189,1245,1249,1250,1250,1274,1277,1277,1275,1310,1305,1303,1327,1328,1327,1327,1329,1331,1331,1331,1331,1331,1331,1331,1331,1331,1331,1331,1331]}],"marks":[{"x":"2025-01-28","label":"DeepSeek-R1 era: China jumps"},{"x":"2025-12-30","label":"Mistral Large 3 lifts Europe"},{"x":"2026-03-31","label":"Gemma 4 lifts the US"}],"yZero":false,"xType":"date"},"sources":[{"name":"LMArena text leaderboard history (overall category), cleaned snapshot table","url":"https://lmarena.ai/leaderboard","licence":"CC BY 4.0 (LMArena data)","captured":"2026-10-07","class":"primary"},{"name":"The Decoder, Reflection Beam report","url":"https://the-decoder.com/reflections-beam-becomes-the-most-capable-open-weight-model-built-outside-china/","licence":"news report (facts only)","captured":"2026-10-07","class":"published-report"}],"news":[{"title":"Reflection's Beam becomes the most capable open-weight model built outside China","source":"The Decoder","url":"https://the-decoder.com/reflections-beam-becomes-the-most-capable-open-weight-model-built-outside-china/","published":"2026-10-06"}],"caveats":["Reflection Beam is not in the Arena data (last snapshot 2026-10-02, before its release). The news supplies its size and licence only; the chart plots no Beam point.","\"Open weight\" uses the leaderboard's licence field, filled from each model's other snapshots where a snapshot had it blank; any licence other than Proprietary counts, including non-commercial ones.","Lab country is by company headquarters, set by us: China (Alibaba, DeepSeek, Moonshot, Xiaomi, Z.ai and others), US, Europe (Mistral, Stability), Other (Cohere, AI21, TII, Upstage and similar). A model named Trinity with no listed org is counted as US (Arcee).","Points are the last snapshot of each month from Jan 2024, plus 2 Oct 2026. Arena scores drift as new models and votes arrive, and are only comparable within a snapshot.","Scores are the default overall text view, not style-controlled or category-specific."],"photo":null,"og":"/media/briefs/open-beam-og.png","ogBytes":24856,"indexable":true,"gateNotes":[],"url":"https://tecntrend.com/briefs/2026-10-07/open-beam","licence":"Text and chart CC BY 4.0 Tec N Trend; underlying data per source licence"}