BOSTON -- Three things we learned from the Red Sox's 2-0 loss to the Cubs on Monday night . . .
1) Cubs pitcher Jake Arrieta has re-invented himself.
Since his rookie season in 2010 for the Orioles, the righty posted ERA marks of 4.66, 5.05 (2011), 6.20 (2012) and 4.78 (2013). This year? That number is down to 1.81.
Red Sox catcher David Ross suggested that it may have been something as simple as a change in where Arrieta stands on the rubber that has him looking downright Madduxian.
Perhaps that's all it took. Perhaps more. Whatever it is, the former fifth-round draft pick is having the type of season that would give hope to any young starter struggling to meet high expectations.
Hear that, Felix Doubront?
2) Jake Peavy continues to tear up the National League.
Though the Red Sox righty's effort wasn't enough when matched up against Arrieta, he had the kind of night the Red Sox would happily live with.
That it came against an NL lineup is worth noting.
Since Peavy joined the Red Sox via trade last season, his success against lineups from the Senior Circuit has seemingly been more than coincidental. In nine starts against National League opponents since coming to Boston, Peavy has a 3.17 ERA and 47 strikeouts versus 19 walks in 59.2 innings (a 2.47 strikeout-to-walk ratio).
Peavy's overall numbers since joining the Sox (including those usually strong starts against the NL): 4.52 ERA and a strikeout-to-walk ratio of 2.13.
Getting those NL performances to translate against American League lineups with full-time designated hitters would certainly help to steady what has been an up-and-down season for the 33-year-old.
3) Mookie Betts still has some work to do in the outfield.
The Red Sox rookie is clearly an athlete, which is why the organization has felt comfortable shifting him from his normal position at second base. But that doesn't mean he has things figured out defensively in the deepest part of ballparks.
Betts was busy in center on Monday night, making four putouts. But a double hit over his head to the base of the wall by Cubs right fielder Nate Schierholtz served as an example of why it will take time for Betts to get accustomed to his new surroundings out there. He appeared to get a late jump, and then gave up on the ball though it looked catchable.
First base coach Arnie Beyeler spent a good deal of time with Betts before Monday's game, hitting him balls off the wall to make Betts more familiar with the park's quirks. There will likely be more of that coming. Betts could figure to not only learn more about the angles in Fenway's outfield, but his jumps on balls have at first glance seemed inconsistent.
It's to be expected to have some growing pains while adapting to a new position at the big-league level. But Betts will have to learn fast if he's to put a stranglehold on a regular role in Boston while Shane Victorino remains out injured.
It won't get any easier for the rookie in Fenway's tricky right field, where he could end up on Tuesday night. Manager John Farrell said he expected Jackie Bradley Jr. to be back in center on Tuesday, meaning Betts will either shift over or end up on the bench to start.