First, let's take a moment to appreciate Hisashi Iwakuma's no-hitter, because no-hitters are awesome.For nine innings on Wednesday afternoon at Safeco Field, the Seattle Mariners right-hander befuddled the Baltimore Orioles, fanning seven, walking three and never allowing a knock to fall.When the final out was recorded on a lazy fly ball to left center field and Iwakuma's teammates surrounded him on the mound, the fifth no-hitter in Mariners franchise history went in the books.It was a singular moment for the 34-year-old Japanese import and a ray of sunshine in a mostly dreary season in the Pacific Northwest."I was feeling great, I felt the fans a lot," Iwakuma told Root Sports' Jen Mueller through a translator, moments after getting showered by a Gatorade bucket. "The fans deserve it. Thank you fans."So that's the small view. Big picture, however, Iwakuma's brush with history means something else.It's the latest evidence of a growing trend, as no-hitters and perfect games become more commonplace and we move deeper into what can now unequivocally be labeled the golden age of the pitcher.It's hyperbole to say that no-hitters have lost their luster. Each one is a unique, thrilling thread in the tapestry of baseball history, and it's still one of the more impressive individual accomplishments in professional sports. But they're definitely happening more often.Counting Iwakuma's outing, there have been four no-hitters in 2015. Last season, we got five; in 2013, we got three, and 2012 gave us seven, including three perfect games.That's 19 no-hitters and counting in the span of four years. Compare that to the 11 seasons between 1998 and 2008, when MLB saw 17 no-nos.Looking further back, here's a handy graph charting every no-hitter since 1900. Note the recent spike that represents a sharp departure from the past two decades:Writing for Deadspin in 2014, Ross Benes tracked the historical trajectory of the no-no:No-hitters declined significantly after the dead ball era and remained quite infrequent until the late 1950s. From the 1960s to the mid-1970s no-hitters became more common than during any other time in baseball history. Pitchers like Nolan Ryan and Bob Gibson were so dominant rules were changed to bring more offense to the game. The pitcher's mound was lowered in 1969and the DH was added in 1973.Following these rule changes, no-hitters tapered off in the late 70s and didn't pick up again until the early 90s. But by the mid-1990s players began crushing more hits and home runs and no-hitters fell off again.So what's causing this most recent uptick' The obvious explanation is MLB's steroid testing policy. While far from perfect, it has led to some high-profile suspensions and has seemingly ended the era of hulking sluggers putting up video-game numbers.There are other factors, however. In 2012, writing for Sports Illustrated, Tom Verducci noted that clubs have begun putting greater emphasis on defensive positioning and slick-fielding players, with a "flood of intelligence in baseball [that] has been almost entirely to the advantage of the defensive side of the game."Then there's the incredible expanding strike zone.Using PITCHf/x data, Jon Roegele of theHardball Timesfound that in 2008, the average size of an MLB umpire's strike zone was 436 square inches. By 2012, that number had ballooned to 456 square inches, and last season, it jumped to 475 square inches.Whatever the cause, or causes, the results are plain. Baseball still boasts its share of big swingersmany of them in the five-tool, Masher 2.0 mold of Mike Trout and Bryce Harper.For fans of low-scoring baseball and exemplary arms, however, this is quite a time to be alive. Iwakuma's gem in Seattle was merely the most recent example of MLB's new normaland it undoubtedly won't be the last.All statistics current as of August 12 and courtesy of MLB.com unless otherwise noted. Click here to read full news..