Bradley-Terry Model with Exponential Time Decayed Log-Likelihood and Adaptive Lasso R package BTdecayLasso version 0.1.1 We utilize the Bradley-Terry Model to estimate the abilities of teams using paired comparison data. For dynamic approximation of current rankings, we employ the Exponential Decayed Log-likelihood function, and we also apply the Lasso penalty for variance reduction and grouping. The main algorithm applies the Augmented Lagrangian Method described by Masarotto and Varin (2012) <doi:10.1214/12-AOAS581>. Software Imports: optimx, ggplot2, stats Yunpeng Zhou <u3514104@connect.hku.hk> Comprehensive R Archive Network (CRAN) Yunpeng Zhou [aut, cre], Jinfeng Xu [aut] GPL (>= 2) 2023-12-07 application/tgz https://CRAN.R-project.org/package=BTdecayLasso doi:10.32614/CRAN.package.BTdecayLasso