<p>This paper introduces a novel research metric indicator entitled “The Leader Researcher Effectiveness Performance Index (L-Index).” The L-Index is designed as an innovative tool to evaluate individual contributions throughout the research process, from the inception to the writing stages of an academic journal paper or book. Our hypothesis is that the primary author typically conceives the idea, establishes the foundational framework, and initiates the initial writing in any document. The L-Index is tailored to assess the consistency and activeness of an author as a leader in various types of research outputs. These outputs include preprints, working papers, journal papers, books, policy papers, reports, and book chapters. This paper presents the theoretical framework of the L-Index and provides examples of its application for analyzing individual author performance. The goal is to demonstrate how these indicators can offer a more precise and clear assessment of an author’s contributions compared to other existing research performance metrics, such as the H-Index and i-10 Index. The L-Index has the potential to enhance the accuracy of evaluating researchers’ performance, providing insights into their leadership roles in diverse research endeavors. Additionally, the L-Index assesses an author’s performance from both an individual perspective and in the context of their networking in research, both domestically and internationally.</p>