A team has finished a game with 21-21-0 runs-hits-errors line 6 times since 1897, most recently Oakland Athletics on 18 June 2000. That is about one every 73,834 team-games.
Box score for the most recent one ↗
21-19-2 21-19-0 21-20-1 21-20-2 21-20-0 21-21-4 21-21-0 21-22-4 21-22-3 21-22-0 21-22-1 21-22-2 21-23-1
The whole distribution — Runs-Hits-Errors Lines · All 18 shapes