The thing about the Mariners, entering this year, was that they weren't supposed to be very deep. They had two legitimate superstars fronting the franchise, a few good-to-great players behind them, and then a duffel bag full of question marks. Most of the season previews looked at those facts, harrumphed, and pegged the M's as a .500ish team (albeit one with unusually high variance, due to the aforementioned question marks' youth).

The funny thing is - they weren't wrong. Despite all of the weirdness that this season has brought us, despite Robinson Cano starting slow and Brad Miller imploding and the entire rotation hitting the DL, the Mariners are a .500 ballclub. Why? Well, it's because they've had two legitimate superstars.

It's just that one of them wasn't expected.

Below is a list of the top 20 position players in baseball so far this year (by fWAR).

It's actually a pretty fascinating list. Just look at the incredible diversity in skillsets! Sure, the top of the rankings are a little predictable - Mike Trout is being Mike Trout, Giancarlo Stanton and Jose Bautista are hitting the crap out of some baseballs, and Troy Tulowitzki is destroying entire worlds with his mind. But numbers 11-20... Jason Heyward is on pace for the best defensive season of all time. Dee Gordon is on pace for the best baserunning season of all time. Nolan Arenado just ripped off a 28-game hit streak. In fact, just about the only thing you don't see on the list is... a catcher.

Why is that? Well, part of it's because the Rockies and Angels have had some insane runs of luck. Part of it is sample-size BABIP shenanigans. But the biggest reason is one of WAR's key flaws: the omission of pitch-framing statistics. Let's add those in, shall we?

The new list:

There he is: Mike Zunino. Lone Mariner on the list. 18th best position player in baseball.

OK, so I'll admit that pitch framing is a bit of a sabermetric fad at the moment. It's unclear whether all of the credit for the extra strikes the Mariners have received should be going to Mike Zunino, and it's unclear whether those strikes are as important as the metrics say they are. But what is clear is this: Zunino has been one of the very best pitch framers in baseball. And that's made him one of the very best players in baseball. And that's what's been keeping the Mariners afloat.

It's not predictive, of course. Mike Zunino isn't likely to really be worth six wins this year. For one thing, both Steamer and ZiPS have him pegged for a power regression in the coming months. For another thing, he's still one of the most hacktastic players in the sport. But the defense - the defense that scouts have always loved - that's real. Baseball Prospectus thinks it's worth 3 wins per year; StatCorner thinks it's worth 2. The power - the jaw-dropping home run power - that's real. There's a reason Dave Cameron called him a star in the making just 18 months ago. And for the first quarter of this 2014 season, that defense and that power have made him one of the 20 best players in the sport.

It's not a sign of permanent superstardom. It doesn't mean he's always going to be one of the best three catchers in the major leagues. It's not a guarantee that he'll run a 110+ wRC+ forever. But it happened. It's been great.

Often, we at Lookout Landing tell you to appreciate Felix Hernandez. He's wonderful, and he's personable, and he won't be around forever. Now, for the first time in a long time, I'm telling you to appreciate Felix Hernandez's batterymate. He's been wonderful, and he's been personable, and his success won't last forever.

Be thankful while it lasts.