On July 28, SK Telecom announced the release of three inference-focused small language models—co-developed with game developer Krafton—that are now freely accessible via the open-source platform Hugging Face.
The models released are OpenThinker2, OpenThinker3, and AceReason-Nemotron-1.1, each featuring approximately 7 billion parameters (7B), specifically designed for high-level math problem solving and code generation. These models leverage Krafton’s proprietary training techniques to enhance performance in these specialized areas.
The co-developed models demonstrated superior performance in the well-known AIME 25 (American Invitational Mathematics Examination 2025) benchmark for mathematical reasoning, surpassing existing models and proving significant technological progress. Math tasks demand complex logical thinking and spatial awareness, and these advances suggest promising applications such as game AI, strategic analysis, and broader real-world problem solving.
During development, SK Telecom contributed by verifying data quality and establishing the training infrastructure, ensuring the models' robustness and stability. Krafton introduced a novel “error review training technique,” which compares correct and incorrect answers to improve both inference accuracy and training efficiency.
This collaboration confirmed the synergy achievable in domain-specific AI model development. Both companies plan to further refine next-generation AI technologies tailored to various industry needs.
Krafton intends to incorporate these models into its game strategy assessment and player analytics platforms. In the mid-to-long term, Krafton aims to develop a variety of large language models (LLMs) in different sizes, bolstering the independence and leadership of Korea’s AI ecosystem.
Kim Ji-won, head of SK Telecom’s AI Model Lab, stated, “Developing high-performance AI language models together has laid the foundation for realizing sovereignty AI (nation’s self-reliant AI). We will continue to contribute to technological sovereignty through close collaboration.”
Lee Kang-wook, head of Krafton’s Deep Learning Division, remarked, “This partnership has demonstrated our capacity for world-class language model development. Based on our proprietary AI technology, we plan to expand AI applications beyond the gaming industry into various other fields.”
