Ultimately, every team is judged by one number in the win column. Anyone can look at that number and take an educated guess at whether it was a good season, a failure or somewhere in between.

The National League Central is competitive and will remain so all year. We can tell that by looking at the win totals, which ranged from 22 to 29 heading into Thursday's slate of games. But what about the numbers behind that number?

Why are the Cubs standing atop the division? How are the Reds holding their own despite some unexpected offensive slumps? What’s put the other three clubs in between Chicago and Cincinnati?

Here’s a look at one key number that helps explain why each NL Central team is where it is.

Brewers: 1.95
As in, Milwaukee’s Major League-leading ERA in 17 games from May 3 until a rare Zach Davies dud on Wednesday afternoon against the Reds.

It’s an arbitrary segment of the schedule, sure, but the pitching in that stretch offers the best explanation for how the Brewers managed to keep their heads well above water through the most difficult portion of their schedule.

Entering May 3, the Brewers were one game above .500, coming off consecutive losses to the Rockies in which they allowed 11 runs in each game, and had the worst starters’ ERA -- 5.49 -- in the NL. The sudden starting-pitching surge prevented further slippage.

Cardinals: 7
That number holds multiple meanings for the Cardinals, who entered Thursday in fourth place.

Their lineup hasn’t produced as consistently as expected in part because they haven’t received star-level performances from Paul Goldschmidt and Matt Carpenter. Those two recorded only seven extra-base hits -- combined -- in the first 18 games of May. Perhaps this usage of the number is no coincidence, then: Entering Thursday’s action, the Cards had scored one run or less seven times this month.

Consider this, too: In their first 48 games, there were only five instances of a Cardinals starting pitcher completing seven innings. The lack of length from the rotation has put a strain on their bullpen.

Looking for a more positive meaning? Add 10. The Cardinals used their primary lineup 17 times heading into Wednesday’s doubleheader, which speaks to the continuity (and good health) they’ve enjoyed. The last time they used one lineup that many times in a season was 2013.

Cubs: 8.4 degrees
That’s the average launch angle created by the Cubs’ pitching staff, a key part of their early success.

One of the concerns for the Cubs going into 2019 was the lack of whiffs generated by the pitching staff. Entering Wednesday, Chicago's average fastball (all types) velocity of 90.8 mph ranked 29th in baseball, so pitching to scouting reports, emphasizing pitcher strengths and employing a strong defense is critical.

So far, the team has excelled on the pitching front (the Cubs' 3.58 team ERA ranked fifth in MLB and their 3.34 rotation ERA ranked third entering Wednesday) and has been doing so by generating weak contact. Per Statcast, Chicago's 5.5 percent weak-contact rate was the second-best mark in MLB. So, while Chicago's arms do not blow lineups away, they have been very effective at avoiding barrels and inducing grounders. That has been a critical factor behind the Cubs climbing to first place in the division.

Pirates: minus-50
After Wednesday's loss to the Rockies, the Pirates had scored 172 runs and allowed 222 runs this season. Their minus-50 run differential led to a Pythagorean record of 18-28, while their actual record was 24-22.

That represents the nature of Pittsburgh’s season -- win close, lose big -- and while it may be cause for concern, it also speaks to the perseverance they’ve displayed. It’s just one of many things they’ve had to overcome to stay afloat.

It’s surprising enough that the Pirates are above .500 considering they have sent 20 players to the injured list this season -- not just role players, either. The Bucs are currently without top starters Jameson Taillon and Trevor Williams, setup man Keone Kela, left fielder Corey Dickerson, third baseman Jung Ho Kang, shortstop Erik Gonzalez, outfielder Lonnie Chisenhall and reliever Nick Burdi. And that’s without even mentioning right-handers Chad Kuhl and Edgar Santana, who will miss the entire season while recovering from Tommy John surgery.

Reds: 46
That’s the number of home runs allowed by the Reds’ pitching staff, the fewest in the NL and a figure that would have seemed unfathomable in recent years. Cincinnati’s pitchers led the league in homers surrendered in each of the past three seasons.

It’s also remarkable because the team plays its home games at homer-friendly Great American Ball Park. Much of the credit could belong to new pitching coach Derek Johnson, who is known for his good communication skills. But the work is being done by pitchers like Luis Castillo, Tanner Roark, Sonny Gray and Tyler Mahle, who have allowed 18 homers -- combined. The Reds may be in last place in the division, but don’t blame their pitching staff. Entering Thursday, the Reds owned the NL’s second-best ERA at 3.50.