The Mariners rank in the top 10 in team ERA and strikeouts per nine innings pitched. (AP Photo/Elaine Thompson)

The Seattle Mariners sit perched atop the American League West six weeks into the regular season. While a few analysts read the tea leaves and prognosticated that Scott Servais’s outfit would be in this position, many more didn’t.

Having amassed a 21-13 overall record, Seattle is in a position that it hasn’t been in a while: leading the division outright. The team’s 6-4 win Tuesday marked its 18th victory in its last 25 games, which per Elias, is the best 25-game stretch for the franchise since 2012. Less than 24 hours later, Seattle wrapped up a sweep of the Tampa Bay Rays.

In fact, it’s been more than a decade since the Mariners last led the division at this point in the season.

“We’re having fun,” Taijuan Walker told the Seattle Times this week. “That was the biggest thing since Day One, is Servais said to just go out there and have fun, and that takes so much pressure off of trying to win.”

While the bats in Servais’s lineup have ample pop — Robinson Cano, for example, leads the American League in home runs and runs batted in — the team’s pitching staff has been the catalyst for the meteoric success.

Worth noting, then, is whether this club can continue to attack the strike zone and pitch its way to a potential playoff berth. The answer, considering the data available right now, is a resounding yes.

Seattle ranks in the top 10 in team ERA, strikeouts per nine innings pitched and expected FIP, among other metrics. This coming from a pitching staff that ranked 22nd in team ERA a season ago and ostensibly didn’t add any superstar talent in the offseason.

Felix Hernandez, Seattle’s ace, is just 3-2 on the year, but has the best ERA (2.27) of any starting pitcher on the roster — and ranks just 82nd in run support among pitchers qualified for the ERA title. While his strikeouts-per-nine-innings average is down (6.8), ZiPS projects the Venezuelan to elevate the figure to 8.92, meaning Servais can expect Hernandez to buckle the legs of more batters moving forward.

Walker, 23, has been terrific, posting a 2.63 ERA and 3.10 FIP. He, like Hernandez, ranks lower 80th in run support among pitchers qualified for the ERA title, and with the team’s bats showing increasing signs of potential — the Mariners’ batting average has spiked from .228 in April/March to .281 in May — there’s reason to believe he’ll have more offensive support moving forward. The Louisiana native leads the pitching staff in WAR and, despite ZiPS projecting the right-hander to see a regression in strikeouts per nine innings, appears poised to post a career year. He has been particularly deft at getting batters to chase pitches low and away.

Nate Karns is 3-1 on the year, posting career highs in strikeouts per nine innings (9.87), and recently outdueled last year’s Cy Young winner, Dallas Keuchel. Dropping the velocity on his curveball to a career-low 81.12 mph, the right-hander is forcing batters to chase the pitch low at an alarming rate, more often than not looking like cartoon characters while they flail at it.

Relief pitching has been nothing short of exceptional: Seattle’s relievers rank fourth in wins above replacement (1.5) after ranking 26th (1.1) a season ago. Opponents are hitting .180 against Seattle’s relievers, the lowest mark in baseball.

“Our bullpen has been lights out,” General Manager Jerry Dipoto told the Seattle Times. “They’ve been the quiet stars of the team.”

The crown jewel of Servais’s bullpen is closer Steve Cishek, whose 11 saves is tied for the American League lead. In his first year with the team, the right-hander has a 0.98 ERA and is setting a career-low in walks allowed per nine innings (2.45). He has peppered the outside corners this season with pinpoint placement.

Nick Vincent, a 29-year-old right-hander, has amassed a career-low 1.84 ERA in 14.2 innings pitched, while fanning a career-high 11.05 batters per nine innings. Additionally, Mike Montgomery and Vidal Nuno are posting the best ERA of their respective careers.

Add to that the recent report that Edwin Diaz, the team’s top prospect, is slowly being converted to a reliever and may join the Mariners this season, and Servais may have a surplus of strong-throwing arms at his disposal.

Moreover, the inter-divisional competition has been lackluster: Only the Texas Rangers rank in the top half of the league in offensive WAR, and both the Oakland Athletics and Los Angeles Angels rank in the bottom 10. Seattle is 12-10 against division foes, an aspect of its schedule that has routinely crippled the franchise’s chances of qualifying for the postseason over the past decade.

In total, Fangraphs projects Seattle to win 86 games this season, good for the top record in the division and the third most single-season wins for the franchise over the past 10 years.

It appeared as though the Mariners entered the season buried up to their necks in players you likely didn’t recognize. But Servais, in his first season at the helm, is steering Seattle toward warmer waters. Should his starting rotation find more run support and his relievers continue their onslaught, the Mariners could be headed for the postseason for the first time in 15 years.