CHICAGO -- The Twins' signing of free-agent catcher Jason Castro this past offseason caused eyebrows to raise.
Castro was guaranteed $24.5 million over three years, and that seemed like a lot of pay a career .232 hitter who had averaged 1.3 WAR over the past three seasons with the Astros.
But this wasn't a standard transaction. It was the first major move for the Twins under chief baseball officer Derek Falvey, and it demonstrated the regime's commitment -- you could almost say devotion -- to run prevention.
Six weeks into the season, Falvey couldn't be happier. Minnesota is two games over .500 in large part because the club has moved from the bottom of the American League into the middle in runs allowed -- 4.8 per game, down from 5.5 in 2016.
Credit not just the emphasis on pitch framing and defensive positioning but a myriad of other factors. The biggest of those are the move of Miguel Sano from right field to third base, better play by shortstop Jorge Polanco and tireless work from Major League coach Jeff Pickler, who was hired away from the Dodgers' front office because of his acumen with analytics.
The Twins are fourth in MLB.com's defensive efficiency ratio after being 29th last season. Like the Reds, who rank second, they are getting big returns on their improved fielding.

Manager Paul Molitor points to his two new catchers, Castro and former Ranger and Indian Chris Gimenez, as the biggest agents of change. He loves how they prepare for games and work with a pitching staff headed by Ervin Santana, Phil Hughes, Hector Santiago and closer Brandon Kintzler.
"We were hoping that making some changes to our catching would add the ability to do some things we can measure a little more accurately -- pitches they get, game calling, preparation, planning ... throwing people out,'' Molitor said. "Both of these guys have done well in all those areas. It's a part of what we''re doing. We put some value on that, for sure, by the decisions we made to go get those guys, and I think we're getting good things there.''
Castro ranked third in the Major Leagues in the number of called strikes caught outside the strike zone a year ago among catchers with regular playing time. Gimenez was in the top one-third of the league.
Elsewhere, Minnesota did not import defensive specialists, but the club is doing a better job utilizing their skills. The outfield is Exhibit A.

It was an absolute mess with Robbie Grossman in left and Sano in right a year ago. But that's turned around completely with Eddie Rosario and Max Kepler playing beside center fielder Byron Buxton.
Buxton, the talented 23-year-old who has labled under unfair comparisons to Michael Trout, has already been worth plus- 5 Defensive Runs Saved, according to FanGraphs. That ranks behind only five other Major Leaguers -- Jason Heyward, Lorenzo Cain, Aaron Judge, Brett Gardner and Kevin Kiermaier). Kepler and Rosario rank among the top-10 regulars in the Majors at their positions.
You can see why Falvey says this is one of the best outfields anywhere.
"I would put it up there with anyone in the game,'' Falvey said.
While Sano opened 2016 as the Twins' primary right fielder -- and wound up worth minus-8 DRS in the 38 games he played there -- Kepler began restoring order when he was promoted last June. He wound up being worth plus-5 DRS, but he is working to get better with Pickler.
"Jeff Pickler's done a lot of work with those guys,'' Molitor said. "They've bought into everything, from the precision of positioning to trying to be a little bit more fearless about making plays, instead of playing tentative. It's been a pretty good combination so far.''
Sano and Grossman are still contributing, but in other roles. While Sano crushes the ball and makes most of the routine plays at third (minus-2 DRS, which ranks 14th among 23 qualifiers at third base), Grossman has a .402 on-base percentage while serving as the primary DH and backup first baseman.
When Falvey was hired away from his role as a pitching specialist in the Indians' front office, he loved Sano's bat, but he wasn't sure about the rest of the package. He's fallen in love with the big fellow, who was a shortstop when Minnesota gave him a $3.15 million signing bonus in 2009.
"I think it's been a great story,'' Falvey said. "The work he put in all offseason, down in Fort Myers at the complex, when nobody was paying attention, he was taking ground balls consistently. I think going out to right field last year was a little bit of a challenge. He came in focused completely on third. He has great hands, we know he has arm strength and I think the athlete you see underneath that big body is showing.''
Polanco, a 23-year-old switch hitter, took the shortstop job away from Eduardo Escobar in Spring Training and isn't giving it back anytime soon. He's fifth among Major League shortstops at plus-2 DRS and leads in some other metrics, including FanGraphs' UZR/150.
This is exactly the transformation that Falvey had in mind when he was hired as a replacement for Terry Ryan.
It's worth pointing out that Ryan valued fielding as much as anyone. The 2016 Twins were more of an outlier than the norm during Ryan's era, as Ron Gardenhire's teams compensated for their low payrolls by having pitchers who threw strikes and fielders who rarely made those pitchers get the fourth out in an inning.
Strong fielding teams are not new to Minnesota. But this one is a welcome sight.