After setting out to prove just how huge of a role defense was playing in the Twins' 2017 resurgence and 19-15 start this season, it was actually a little overwhelming to see how much positive data there was.

Whether we're talking about traditional data or more advanced metrics, the Twins not only are light years ahead of where they were last season but they are also becoming one of the best defensive teams in baseball.

Perhaps that shouldn't be a shock given the Twins made genuine attempts to upgrade their defense in the offseason, but it's hard to imagine anyone would have predicted things would go so well. Jorge Polanco and Miguel Sano, a duo that some thought would sink the left side of the infield, entered Tuesday having combined for just four errors. Upgrades at catcher and the outfield have been startling. Add it up, and you have this:

• The Twins entering Tuesday had made just 10 errors in 34 games. That was tied with the Royals for the fewest in the majors What's interesting within that total is the Twins have made just two throwing errors all season. By contrast last season, the Twins made 126 errors (second most in the majors), of which a whopping 54 were throwing errors.

• Twins catchers Jason Castro and Chris Gimenez have been a huge upgrade over last year's catchers, Kurt Suzuki and Juan Centeno (and a little bit of John Ryan Murphy). Consider that last year Twins catchers allowed 83 wild pitches and nine passed balls (a combined 92 times where at least one runner advanced at least one base). This year, Twins catchers have allowed just 10 wild pitches and two passed balls (on pace for fewer than 60 combined this season).

Last year the Twins allowed 78 stolen bases and threw out just 20 would-be base stealers. Twins catchers this season have allowed 17 stolen bases while throwing out eight runners.

The Twins are vastly improved on defense this season compared to last, from the surprising nimbleness of Miguel Sano at third base to the expected all-around proficiency of catcher Jason Castro.

Pitch framing data varies from site to site, but according to Baseball Prospectus, Castro — who came in with a reputation for being good at it — is doing well with the Twins this year. Per BP, he's on pace for plus-seven framing runs, which is a little lower than previous years with Houston but still good and somewhat expected given he's working with a new staff.

• The cumulative impact on advanced metrics is that the Twins, per FanGraphs, are third overall in MLB with plus-10.1 defensive runs saved so far this season. Last year? Yeah, not good. Terrible, in fact. The Twins were minus-45.7 in that department, which was second worst in the majors.

• All of those things line up with the eye test. The Twins' outfield defense has spectacular range. I don't know how many times a Twins pitcher has applauded and/or fist-pumped when an outfielder ran down a ball he had no business getting to, but it's been a lot.

The net effect is to make a pitching staff with a lot of holes look at least decent. The Twins' team ERA entering Tuesday was 4.23, good for 17th in the majors. But they were tied for last in strikeouts (227, which is 78 fewer than the MLB average). Other advanced metrics show the staff has benefited greatly from defense.

The Twins have excelled in all phases of the game at various points of the season. But their defense has been the most consistent and most important factor in their resurgence.