Providing subscription-based temporary use of on-line non-downloadable software for facilitating fantasy sports and esports play and participation, for the creation, modification, and submission of single or multiple online entries to online sports and esports contests using mathematical modeling, for tracking fantasy sports and esports performance and contest data, for allowing users to evaluate player performance statistics and monitor real-time player and location variables to predict future outcomes, to provide information and articles about fantasy sports, fantasy esports and actual sports and esports, and to provide video instruction spertaining to the optimum use of the software, all in an interactive website.