By run differential the Cubs are +33, right in line with their 35-27 record. They've scored 4.56 runs per game while only allowing 4.03 runs per game. BaseRuns thinks they've actually been among the luckiest teams in MLB so far, gaining 5 extra wins on account of sequencing. By BaseRuns calculations the Cubs should be scoring 4.45 runs per game while allowing 4.55 runs per game. Looking at their team pitching stats backs that up, showing they have probably been stranding runners at an unsustainable clip with a 77.4% left on base rate, 2nd in MLB, which has resulted in a team ERA of 3.73 compared to a FIP of 4.29, the second largest negative differential in MLB. Lots of indicators that their pitching is in for some pretty notable regression as the season progresses, which is probably why the projections still favor the Brewers at this point with division odds of 64.6% vs 29.6% (PECOTA), 57.4% vs 27.0% (FanGraphs) and 45% vs 38% (538).