Active members of the Baseball Writers Association of America (BBWAA) for 10 or more years decide who should be included in the HOF.
Initially, membership in the BBWAA was comprised only of newspaper writers. Rules were loosened after 2000 — allowing prominent internet-based journalists to become members of the BBWAA. This change was made because the number of newspapers in the U.S. has rapidly dwindled, and baseball coverage has taken on new forms, especially through the internet.
Once a player is retired after five seasons, is professionally worthy, and is in good standing (i.e., has not been banned from baseball), he is placed on the ballot for inclusion into the Hall.