The Cubs are the best team in baseball at present. We know this. We've known it for most of the season, save one bad and one awful stretch. They have one of the most dangerous offenses in the league, have built a back-end of the bullpen that -- once Pedro Strop and Hector Rondon return from injury -- will be dominant and their starting rotation has performed as the best in baseball throughout the year.

On the latter point, the rotation has had a ton of help from an unheralded portion of this team. Yes, it's the defensive end of things.

As for the errors and fielding percentage, those are the middle of the pack. That doesn't matter. Oh, I know some think it does. It would if the teams performed differently in the category. They just don't. Every team in the majors is between .978-.988. That's one percent between the best and worst, which is obviously negligible. Basically, they are all the same.

What really matters is range teamed with the ability to avoid errors. As noted, every team is outstanding at not making errors on the whole. We further know that one cannot make an error on a ball in play he cannot reach. That's range, and the Cubs separate themselves by getting to balls in play better than anyone.

Addison Russell is one of many great Cubs' defenders. USATSI

Using the Defensive Runs Saved metric from Baseball Info Solutions, we see a blowout in favor of the Cubs. Through Tuesday, the Cubs' defense had saved 82 runs more than the average NL team. Second was the Giants at 60 before it dropped all the way down to the Dodgers at 39.

We can do better than that, though. How about defensive efficiency? Sure, the name will scare off the closed-minded, but it's the the percentage of balls put into play that are converted into outs. That seems the mark of a good defense, no? Think of it at the most basic, Little League level. The ball is put in play by the offense, and the team that converts the highest percentage of those balls into outs has to be pretty good, collectively, at defense. It's common sense.

Sure, in a small sample, that can be fluky. Over the course of more than 125 games, though? C'mon. That's a wholly legitimate pattern.

The Cubs entered Wednesday at a .745 clip, which ranks in the top 50 in baseball history. Of course, we know the climate is different nowadays, so it's worth mention this is the highest total since 1982 (Padres). Oh, and when Baseball Prospectus puts in a park-adjustment factor -- as we know, the variation in defensive conditions through baseball history is vast -- the Cubs are ...

The best in baseball history.

Really, they are. The 2001 Mariners are second with the 1999 Reds, 1975 Dodgers and 1990 A's rounding out the top five. The gap between the Cubs and Mariners is bigger than between numbers two and five, too.

How are the Cubs doing it? With consistency, talented defenders, versatility, depth and some pretty outstanding highlight-reel plays. Let's touch on all of that.

Catchers

David Ross has been exceptional defensively this season, helping the Cubs to rank fifth in the NL despite Miguel Montero pretty much falling apart defensively in front of our eyes. Among catchers with at least 1,000 plate appearances (which isn't a ton; Yadier Molina had 4,186 entering Wednesday), Ross has the best catcher's ERA and it's a huge lead. He sits at 2.42, with Rene Rivera's 2.83 being second in the majors.

Ross is about league average in throwing runners out at second (and here we'll note one weakness of the Cubs' pitchers is holding runners on base, as several are terrible at it), but he leads the majors with five pick-offs.

Oh by the way, Cubs rookie backstop Willson Contreras is third with three pick-offs. There are only three catchers in all of baseball with more than two and the Cubs have two of the three (former Cub Dioner Navarro is coincidentally the other).

Despite the staff issues in holding runners on, Contreras actually does throw out better than average (27 percent), as he's caught eight of 23 (35 percent) would-be base-stealers this year.

The Infield

The regular starters are Anthony Rizzo, Ben Zobrist, Addison Russell and Kris Bryant.

Rizzo at first is very good. He bails out his infielders at times with good scoops and is pretty adept at crossing over first when need to in order to grab misdirected throws. As for a range component, DRS only likes Brandon Belt better in all of baseball.

Many of you have seen this ridiculous play by now, too:

Zobrist is steady at second, but nothing really special, notably when range factors in. There's an uptick here that we'll get to later, though.

At short, Russell is exceptional. In fact, even with peers like Andrelton Simmons, Francisco Lindor and Brandon Crawford, he leads all shortstops in DRS. This play on Wednesday night at a huge spot in the game is a nice example of Russell's defensive chops:

Bryant at third isn't great, but he's perfectly adequate. He'll make great plays on occasion, too.

The wild card is Javier Baez. He can play all four infield positions and has done so enough to show up at 16th in all of baseball in DRS, despite having not logged even 800 innings on the season (Russell is approaching 1,100, for comparison's sake). Baez has already posted positive DRS values at second, third and short and he's actually trailing only Ian Kinsler and Dustin Pedroia at second, despite this being a cumulative stat and Baez having only started at second 32 times.

He makes plays like this from pretty much anywhere:

And it should be noted that Baez is the best tagger in baseball, at least when it comes to catching would-be basestealers. This has happened more than a handful of times:

The Outfield

The outfield isn't quite as impressive individually (save for one guy and we'll get to him), but left fielders rank fourth in DRS in the NL, center fielders are tied for first and right fielders are first.

The individual who carries the day here is Jason Heyward. He leads NL right fielders in DRS and is actually 18th overall in all of baseball thanks to the value he's provided, when needed, in center. He has the arm:

And the range:

Heyward is a major part of the overall score, but depth and versatility have been huge. The Cubs have positive DRS figures in the outfield this season from Zobrist, Bryant, Dexter Fowler, Albert Almora, Matt Szczur and Chris Coghlan. Yes, two infielders have provided positive value in the outfield. That's how Baez gets into games and this actually maximizes the team's defensive value (as Jorge Soler rates out as a minus-defender).

Overall

Going back to Baseball Info Solutions' Defensive Runs Saved (DRS for short), the Cubs are the only team in the majors to not have a negative value at a single position. The worst is third base at zero. That's mostly Kris Bryant, who is reasonably average at third. Again, that's the "weak" spot. And Bryant at third base isn't weak. He's average.

Even the pitchers rate out as a plus-six in DRS, which trails only the Cardinals (15) and Giants (9) in the NL.

We've already noted that the team has the top DRS mark and is the best in MLB history at converting balls in play into outs. There aren't weaknesses overall at any individual position, either.

So if you're wondering how the Cubs lead the majors in ERA and are lapping the field in rotation ERA, there's more to it than having good pitchers. Those pitchers have incredible support behind them -- one of the best support systems we've ever seen.