Here is a brief explanation of the new format taken from Jayson Stark's piece in The Athletic:
The 2023 schedule will cut back on rivalry games. And in their place, teams will play an NBA-like schedule that involves facing all 29 other clubs, including every one of the 15 in the other league. Here’s a breakdown:
DIVISION GAMES (56): Clubs play all four teams in their division 14 times. (Current total: 19) So that means one three-game series and one four-game series each, both home and road.
OTHER 10 LEAGUE OPPONENTS (60): Those non-division teams within your league? You’ll play them six times apiece — three at home, three on the road. (Current total: six or seven apiece)
INTERLEAGUE SCHEDULE (46): Here’s how this works: Every team plays its interleague “rival” (Mets-Yankees, Cubs-White Sox, you know the deal) four times — two at home, two on the road. (Current total: four or six games, depending on the season)
As for the other 14 teams in the opposite league, you’ll play three games against every one of them. Half are at home. Half are on the road. Then that will flip the following year.