Replication package for: Who gets the credit? Win probability added and the Impact Player rule in Twenty20 cricket

Replication package for the manuscript "Who gets the credit? Win probability added and the Impact Player rule in Twenty20 cricket" (submitted to the European Journal of Operational Research). It reproduces every number, table and figure in the paper. The package contains ball-by-ball data for 1,243 Indian Premier League matches (2008–2026; 295,732 deliveries) derived from the Cricsheet archive, Impact Player substitution events, the Python analysis notebook and scripts (win-probability models evaluated by leave-one-season-out cross-validation, win probability added per delivery, and the comparison of Impact Player substitutes with starters), all result files, the figure scripts, and a log of modelling decisions. See README.md for the run order. The input data come from Cricsheet (https://cricsheet.org/) under the Open Data Commons Attribution License 1.0. The analysis code was written with the assistance of Claude (Anthropic) and checked by the author.