A team has finished a game with 20-18-2 runs-hits-errors line 1 time since 1897, most recently New York Yankees on 19 June 2002. That is about one every 443,004 team-games.
Box score for the most recent one ↗
20-16-0 20-16-5 20-17-0 20-17-2 20-18-0 20-18-1 20-18-2 20-19-0 20-19-2 20-19-1 20-19-5 20-20-3 20-20-2
The whole distribution — Runs-Hits-Errors Lines · All 18 shapes