Which 16-year-old programmer helped port early Tetris to the IBM PC?

The 16-year-old programmer who helped port early Tetris to the IBM PC was Vadim Gerasimov.

Gerasimov was a Soviet computer programmer who worked with Alexey Pajitnov and Dmitry Pavlovsky on an IBM PC version of the game. The original Tetris had been created by Pajitnov in 1985 on an Elektronika 60 computer, and the IBM PC port helped the game spread beyond its original research-computing environment.

The port was written in Turbo Pascal and circulated on floppy disks through Moscow and other parts of Eastern Europe. Gerasimov's technical work was especially important because IBM-compatible PCs were far more accessible internationally than the Soviet computer on which the first version had been developed.

The alternatives represent different figures in the licensing story. Robert Stein was the Western software executive who pursued commercial rights, Henk Rogers later negotiated important Japanese and Nintendo rights, and Dmitry Pavlovsky was another collaborator rather than the teenager identified in the question.