The Battle of Noryang is widely recognized as a pivotal engagement of the Imjin War, having long received significant scholarly attention. However, the vast majority of known historical records related to this battle were not written by direct participants. These accounts, each with their own perspectives and emphases, contain substantial contradictions that have yet to be effectively resolved. In November 2022, the public release of a series of new artifacts reignited interest and debate in South Korean society regarding Yi Sun-sin and the Battle of Noryang. This article utilizes a letter from a soldier who survived the battle as a key piece of evidence to examine the historical narratives concerning the respective military achievements of Yi Sun-sin and Chen Lin during the events surrounding the engagement. By doing so, it aims to contribute new evidence to the historical discourse on this battle and add to the ongoing vibrant discussion on the topic. Korean sources emphasize Yi Sun-sin's contributions to the Battle of Noryang. While they do not entirely lack positive remarks about Chen Lin, some records question his merits, even suggesting that he “usurped others' achievements as his own.” Furthermore, there are claims that during pre-battle deliberations, Chen Lin delayed dispatching troops or even advocated for peace negotiations on behalf of the enemy. Some narratives state that Chen Lin only reluctantly followed suit after Yi Sun-sin insisted on engaging the enemy. Chinese sources all center their accounts of the battle on Chen Lin. Among these, the Record of the Eastern Expedition(东征记) provides the most detailed description. Within this narrative framework, Chen Lin is portrayed as resolute in his stance against the enemy, decisive in deploying forces, and having obtained crucial intelligence beforehand about the enemy fleet setting sail during the third watch. Based on this, he is credited with the merit of “sounding the great drum and advancing first,” displaying “lightning-fast” momentum, and demonstrating bravery by “placing himself in a fatal position.” There is no mention whatsoever of any disagreements with Yi Sun-sin, delays in troop deployment, or actions aimed at negotiating peace on behalf of the Japanese. Using the letter from the surviving Ming soldier under Deng Zilong's command as a clue allows for a reconstruction of the advance of the Ming-Korean allied forces during the Battle of Noryang, and further enables an assessment of the accuracy of the aforementioned historical narratives. The actual situation on the night of the battle appears to be that Yi Sun-sin departed during the second watch and arrived at Noryang in the fourth watch to commence battle, while Deng Zilong and Chen Lin departed during the third watch and arrived at Noryang in the fifth watch to join the engagement. Considering the final outcome and the difference in rank between Chen Lin and Deng Zilong, it is highly likely that among the three, Yi Sun-sin arrived first, followed by Deng Zilong, with Chen Lin arriving last. According to this analysis, both Chen Lin's time of departure and arrival at the Battle of Noryang were one watch later than Yi Sun-sin's. The Record of the Eastern Expedition has a clear partisan stance and a strong tendency to highlight Chen Lin's personal role. Arguably, the choice to omit the departure times of Chen Lin and Deng Zilong and record only their arrival time at Noryang, likely for narrative purposes and to show coordination, seems to carry a definite intent to conceal this discrepancy.