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7/3/2014 1:22 P.M. ET

Five reasons for Mariners' recent success

Excellence from King Felix and staff, support for Cano leading to improvement

CHICAGO -- When the Mariners signed Robinson Cano last winter, many around baseball wondered why Seattle was paying so much money for one star without pursuing other big-time talent to bolster a squad that hadn't made the playoffs since 2001 and was coming off a fourth straight losing season.

But the Mariners felt they were close to turning the corner with a young club that had been growing together the last few years. And with the season now past the halfway point, Seattle has proven to be one of the American League's biggest surprises with a 47-38 start -- a 10-win improvement from last year's 85-game mark.

Here are five reasons why the Mariners are flourishing:

1) Felix is having his best season
There was a feeling in recent years that Felix Hernandez had done everything possible, but the Mariners just hadn't been able to cash in due to lack of a supporting cast. Turns out, Hernandez could indeed be better … as he's been through his first 18 starts. The King worked hard over the offseason to get stronger in his lower body, and the result has been a few more mph on his fastball, which makes his nasty changeup all the nastier.

Pick a stat, any stat, and Hernandez is putting up the best numbers of his career, even better than the peripherals he posted in 2010, when he was so dominant across the board that he earned the AL Cy Young Award even with a 13-12 win-loss record.

This year, Hernandez is being rewarded for his excellence. He's 10-2 with a 2.10 ERA. His WHIP and FIP are career lows, his strikeout-to-walk ratio a career high. In short, he's putting up a Cy Young-caliber season by any measure … and getting better run support in the process. All of which adds up to an ace in the right place.

2) Pitching, pitching, pitching
It takes more than Hernandez to put together the best team ERA in the league, and that's where the Mariners find themselves 85 games into the season. Seattle not only leads the AL with a 3.20 mark, they have easily the largest improvement of any MLB team in ERA this season, as they've lowered that number by 1.11 runs per game from last year's 4.31.

The Mariners are on pace to allow 551 runs this season, compared to 754 in 2013.

Despite losing All-Star right-hander Hisashi Iwakuma to injury for the first month and just now getting top prospect Taijuan Walker into the rotation after arm issues, Seattle's starters have the second-best ERA in the AL thanks to strong contributions from rookie Roenis Elias (7-6, 3.96 ERA) and veteran Chris Young (8-4, 3.11 ERA), who is a strong early candidate for the Comeback Player of the Year Award after overcoming years of shoulder problems.

Top it off with the league's best bullpen with a 2.53 ERA, and it's not hard to see how things have fallen into place for new manager Lloyd McClendon and his staff.

3) Cano isn't doing it all by himself
While Cano has hit only six home runs to date, he's lived up to all expectations by batting .323 with 51 RBIs, 19 doubles and a .382 on-base percentage. The veteran second baseman has provided a missing force in the middle of the order while being a willing leader for a young team eager to follow his professional approach at the plate.

Young third baseman Kyle Seager has been a huge beneficiary of hitting behind Cano and has responded with a breakout first half in which he's put up a team-leading 13 homers, 59 RBIs, .500 slugging percentage and .855 OPS. Those numbers are not only as good as any third baseman in the league, they're better than Cano's production at this point.

Rookie center fielder James Jones has also provided a big boost since his promotion in May, giving the Mariners some needed speed in front of Cano. Shortstop Brad Miller got off to a horrible start at the plate, but he rebounded with a strong June during which his .512 slugging percentage was second only to Seager's .536 on the team. Young catcher Mike Zunino leads all AL catchers in home runs, right fielder Michael Saunders has been productive when healthy and veteran Endy Chavez and first baseman Logan Morrison have provided recent boosts to the offense as well.

4) You've got to glove it
McClendon is a former hitting coach with the Tigers, but he knows the value of defense as well. And one of the first things he said was that his club had to get better in that area, particularly in the outfield after playing much of 2013 with slow-footed Michael Morse and Raul Ibanez in the corners.

Without question, the Mariners are much improved with the gloves this season, which is part of the reason the pitching numbers are much better as well. Cano brings a Gold Glove at second base, an underrated part of his game. Seager is a solid third baseman as well, and Justin Smoak and now Morrison at first have played that position well, while Miller has overcome a rough start in the field as well as at the plate.

The biggest differences, though, are in the outfield, where Dustin Ackley, Jones and Saunders are far more athletic and cover a lot more ground than last year's group, and behind the plate, where the 23-year-old Zunino has been a major upgrade in his first full season.

There are lots of defensive metrics that show the Mariners' improvement, but the most tangible evidence is the AL record streak of 46 straight games from May 12-June 30 without allowing an unearned run that finally was snapped Saturday. The only longer streak in MLB history, dating back to 1914, was a 48-game stretch by the Cardinals in 2009.

The Mariners currently lead the AL in fielding percentage after finishing ninth a year ago.

5) Smaller moves paying big dividends
Sometimes little things add up, and the Mariners have found success with some less-heralded additions that have provided depth and veteran presence to the young nucleus. Young has been a huge boost after signing a one-year, $1.25 million deal following his release by the Nationals.

Joe Beimel, a lefty reliever who hadn't pitched in the Majors since 2011 due to elbow problems, has been lights-out with a 1.40 ERA in 28 appearances after signing as a Minor League free agent. Veteran catcher John Buck has been an excellent mentor for Zunino, Willie Bloomquist has provided a steady presence as the ultimate utility man and Chavez delivered a surprising spark in the past month as another veteran on a Minor League deal.

Some eyebrows were raised after general manager Jack Zduriencik signed Fernando Rodney to a two-year, $14 million deal. But the 37-year-old has greatly stabilized the bullpen by providing a veteran closer and allowing talented, younger relievers like Tom Wilhelmsen, Danny Farquhar, Yoervis Medina, Charlie Furbush and Dominic Leone to fit into roles in which they've flourished.

And overseeing it all has been McClendon, the first-year manager who has brought a combination of confidence, intensity and encouragement that has blended well with a team that believed before anyone else that it, indeed, had what it takes to compete in the rugged AL West.

Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.