We're two-fifths of the way through the regular season and boy, are my arms tired. Over the first 60-plus games, a whole host of new names has popped up on our radar for our attention while old standbys have fallen off. Nowhere is that more true than with the early favorites for the National League Cy Young Award.

Matt Cain has a 5.45 ERA. Cole Hamels is 2-9, 4.56. Tim Hudson has a 4.48 ERA. On the flip side, NL ERA leaders include Shelby Miller (22 years old), Patrick Corbin (23), Jordan Zimmermann (27) and Matt Harvey (24). With the youth movement afoot, let's dive further into the numbers and look at our early Cy Young favorites.

Adam Wainwright

In 89 innings, Wainwright has struck out 84 and walked only six, for a strikeout-to-walk ratio of 14-1. Among all starting pitchers since 1901 to toss enough innings to qualify for the ERA title, only two have finished with a double-digit strikeout-to-walk ratio: Bret Saberhagen (11.0) in 1994 with the Mets, and Cliff Lee (10.28) in 2010, splitting time with the Mariners and Rangers. Wainwright has had more games with zero walks (seven) than games in which he walked a batter (five). At his current pace, Wainwright would easily eclipse Saberhagen's record.

Wainwright's 2.33 ERA is only sixth best in the league at the moment, but since we haven't seen a pitcher finish a season with a sub-2.00 ERA since Roger Clemens (1.87) in 2005, he is certainly in Cy Young territory. Strikeouts and walks are also the best measure with which to predict future success, so we should expect him to keep a low ERA for the rest of the season and gain ground on everyone else. His skill interactive ERA (SIERA), an ERA estimator, is an MLB-best 2.67.

Shelby Miller

Miller, Wainwright’s teammate, is enjoying his first full season in the majors and could very well go home with both the NL Rookie of the Year Award and the NL Cy Young Award. Miller currently has a league-best 1.91 ERA thanks to four starts (of 11) in which he allowed zero runs while tossing at least six innings. In a rotation that has endured some hardship -- Chris Carpenter, Jaime Garcia and Jake Westbrook have all been incapacitated in one way or another -- Cardinals fans have quickly come to depend on Miller and they haven't been disappointed.

Although Miller won't keep his ERA in the ones, his strikeout and walk rates are eerily similar to those of Wainwright in previous seasons, so he won't fall too far off if those rates hold. However, Miller has faced only the Brewers, Pirates and Giants multiple times. As he goes up against the rest of the opposition for a second and third time and the league builds a book on his tendencies, we will learn more about Miller's staying power. For now, though, he is the leading candidate for the NL Cy Young Award and the favorite to start for the NL in the All-Star Game in July.

Matt Harvey

When I was a kid, we used to play a variant of "tag" that included safety zones. So long as you were touching the designated tree, you couldn't be tagged by the person who was "it." For Mets fans, Harvey's scheduled start is that safety zone every fifth day where the rest of the league can't pound on them. No, really. The Mets are 8-4 in Harvey's starts and 15-29 every other day. "Harvey Day" is to Mets fans what Friday is to office workers of the world.

Harvey wasted no time establishing himself among the league's best. He had a 0.93 ERA through his first four starts, all wins, making him the first pitcher in the modern era to win all four of his starts to begin a season while allowing 10 or fewer hits. Over a longer frame of time, he became the first with 125 or more strikeouts and 25 or fewer earned runs allowed in his first 17 career starts. There is no shortage of ways to put Harvey's early performance in a historic light.

In his most recent start, he allowed four runs in five innings to the Marlins, his first objectively poor start of the season. His ERA rose all the way to 2.17. Unless Harvey strings a bunch of those starts together, he will be around at season's end when we are once again debating who should go home with the hardware. We all know wins can be overrated, but in a season with so many candidates, Harvey's lack of run support could hurt him; he's 5-0 but has earned no-decisions in seven of his past eight starts.

Clayton Kershaw

Kershaw is only 25 years old, but is talked about as if he is a grizzled veteran. In some ways, he is, as this is the lefty's fifth full season. He has encountered very few issues over that time as he works his way toward becoming his generation's best starting pitcher.

He has a 1.93 ERA through 13 starts and it seems as if no one is talking about it. Considering the way his Dodgers teammates have been falling like flies to injuries, his performance stands out even more. His strikeout and walk rates are nearly identical to last year's, when he finished second in Cy Young balloting to R.A. Dickey.

One aspect of Kershaw's game that gets overlooked is his ability to generate weak contact. His infield popup rate is the seventh best in the league at 13.3 percent, according to FanGraphs. Along with his 25 percent strikeout rate, two out of every five plate appearances lead to an out without any hope for base advancement. That is a great recipe for success, and it's why he is one of two NL starters (along with Miller) currently sitting on an ERA below 2.00.

Jordan Zimmermann

With an honorable mention to Patrick Corbin (9-0, 2.06 ERA) and Cliff Lee (7-2, 2.45, but could be traded to an AL team), it is Zimmermann who rounds out my top five. This success is nothing new for the Nationals right-hander, who posted a 3.18 ERA in 2011, 2.94 last year, and is currently at 2.16. In that time, he has the eighth-lowest walk rate among qualified starters at 4.7 percent, just a few ticks shy of leader Lee at 3.9 percent.

Zimmermann doesn't have overpowering stuff, but succeeds by keeping runners off the bases by limiting walks and inducing weak contact. His 17.3 percent infield popup rate is the best in baseball at the moment, and his 51.5 percent ground-ball rate is the 12th highest. One might think that relying on success on balls in play is a recipe for disaster, but Zimmermann has been doing this for nearly 500 innings and has shown no signs of slowing down.