The Theorem is this little thing where baseball people predict win/loss record based on runs for and runs against. Historically the Brewers beat the theorem and take the division and make the play offs.
Last year the Theorem and the Brewers actual win total were in agreement that the Brewers should have won 95 games.
In every other year since 2015 the Brewers have out performed, in wins, their expected wins based on runs for vs runs against.
There are different theories on how to do this, but basically a team beats the theorem by winning close games and not worrying if a loss is by 4 runs or 14 runs when losing.
The Brewers historically have done this through pitching that keeps games close, defense that doesn't blow leads, and a top notch A bullpen to close out those close games. They also tend to be ok with trying different pitchers during garbage time. Sometimes these pitchers become A bullpen contributors. Sometimes they just inflate that run differential and lose their jobs later in the season.
After 20 games the Brewers had scored 3 more runs than they had given up. The theorem believed that they should have been 10 -10 on the season. They were 13 -7. Already three games ahead of the theorem.
At this pint in the season the Brewers are 58 - 50 with 500 runs scored and 464 runs allowed. Their actual record and their theorem projected record are the same. And they are 2 games behind the Cardinals and wouldn't make the playoffs if they started today. And if you look at the record against the theorem since the first 20 games, they are trending in the wrong direction.
The Brewers won without beating the theorem in 2021 because of the talent level, especially starting pitching, being that much better than anyone else in the division. Either that talent level has to demonstrate itself over the rest of the season or the Brewers have to return to theorem beating baseball.
I'm not sure if the current roster has the defensive chops or late inning lead protection ability to beat the theorem this year. The team isn't built specifically to win close games in the same way.