I'd like to take a look at starters' success in the first half of baseball, and perhaps make some guesses at Cy Young candidates (which I will probably revisit later in the season). Since I don't know the AL as well, I'll start there...
AL aces at the ASB
A big reason the White Sox have had great success is that Chris Sale has been a complete badass so far. At 2.56 FIP, his season has been unpredictable to say the least. Even ZiPS didn't quite figure it out, but he was forecasted at 3.47 FIP so it's not totally from out of nowhere. The updated projection is 2.96 FIP. His 3.21 xFIP is also astounding, and his ERA is a staunch 2.21. Since this is an all inclusive rate stat fanpost, Sale's tERA is 3.01 and SIERA at 3.23. Since my gimmick is averaging all those together to compare overall, the average of all those stats is 2.844. (101.2 IP)
Verlander is again in the running for best pitcher in the AL. His FIP is at a miserly 2.94, which is right around his projection. While he may not be as lights out as Sale in the first half, he has pitched many more innings... only Felix Hernandez comes close to 132.2 IP. His K/BB ratio is also better than Sale's... and his xFIP is closer at 3.31. His results by ERA are also quite impressive at 2.58. The more esoteric rate stats are 3.37/3.26 by tERA and SIERA. His BABIP is lower than Sale's though, so maybe he will regress a little more, but it's not that big of a difference tbh. Average of rate stats: 3.092.
Weaver is the leader by the traditional Earned Run Average stat at a measly 1.96. However, he is also the most likely to regress since his BABIP is .223. FIP-wise, Jered matches Justin's at 2.94. xFiP is 3.93 though. 3.31/3.90 by tERA and SIERA. Also, Weaver hasn't cracked 100 IP yet, further making him a questionable Cy Young candidate at this point. 3.208 averaged rate. Weaver's updated ZIPS projection is 3.06 FIP and 2.54 ERA.
An ace many Cardinals fans covet, perennial Cy Young contender King Felix is at 2.96 FIP, 3.13 ERA, 3.23 xFIP, 3.60 tERA, and 3.25 SIERA. Felix Hernandez is right around his projections, and the update is 3.00 FIP. The average of the five rate stats is 3.234, and he has pitched a strong 123.2 IP, putting him just off Verlander's pace. One last thing about Felix: his BABIP is the highest of these top 5 AL pitchers, so he could be a sleeper (.324 babip against)
The Yankee's mighty ace and another perennial Cy Young contender, CC Sabathia is at 3.21 FIP, 3.45 ERA, 3.25 xFIP, 3.77 tERA, and 3.33 SIERA. His updated projection is 3.29 FIP, and CC has pitched 107 innings so far... I feel compelled to note along with his IP that the Yankees have one of the best bullpens in all of baseball. The average of the 5 rate stats is 3.402. (babip against is .315, also much higher than the other leaders)
NL aces at the ASB
Over in the NL, or the original league, Zack Greinke is boss so far. A 2.35 FIP in 111 IP is awesome. Actually, awesome might be an understatement. That's right, a freakin' 2.35 FIP. Wow. ERA not quite as impressive at 3.32, but xFIP is 2.76. Those weirdo other stats, tERA and SIERA: 2.97/2.94. One might ask, is he outperforming his projections? Yes, but only by a little: 2.61 ZIPS projection, update is 2.47. All of this he has done with a .335 BABIP against. Averaged rates: 2.868. (111 IP)
Stephen is proving that he is still a pitching phenomenon with a FIP at 2.50, an ERA of 2.82, the lowest xFIP in the NL at 2.61, a K/9 of 11.64, 2.93 tERA, and 2.59 SIERA. His updated projection is a 2.55 FIP. His averaged rate stat is 2.69! Only 99 IP so far though, making him 3rd with teammate Gio Gonzalez in fWAR in the NL. (.317 BABIP)
I must admit (yes, NCAYFT disclaimer) that I totally lucked out this year on my starting rotation. I drafted for hitting and took a flyer on Gio Gonzalez, figuring he may be a 4th or 5th in the rotation type. But this year, he is actually more like a Strasburg type at 2.52 FIP, 2.92 ERA, 3.06 xFIP, 3.29 tERA, and 3.29 SIERA. 101.2 IP with an averaged rate stat of 3.016. What really separates him from those top two pitchers is his BABIP against is .264.
These last two top 5 NL pitchers (by FIP) are really the most surprising of ERA leaders over the first half of baseball. While Dickey has a very respectable FIP of 2.76, his ERA is 2.40. By xFIP/tERA/SIERA: 2.86/2.95/2.86 in 120 IP! Dickey has been quite good, maybe even better than Greinke with an average rate stat of 2.766. However, he is a prime candidate for regression with a .258 BABIP against and an updated projection of 3.09 FIP.
Who? About a quarter through the season I took another flyer on a pitcher, James McDonald of the Pittsburgh Pirates, and boy did that pay off so far. The NL Central's other ace in first place is someone many still probably don't even know about. At the beginning of the season, James was projected for a 3.86 FIP by ZIPS. They didn't get this one too right. The updated projection is now 3.31 FIP. In reality, he has a 2.97 FIP, 2.37 ERA (2nd in NL), 3.59 xFIP, 3.50 tERA, and 3.57 SIERA. Whatever he is doing has been a bit of smoke and mirrors though, since his BABIP against is .242. He has pitched a respectable 110 innings though. Averaged rate stat: 3.2.
So I think my prediction would have to be Justin Verlander again in the AL for Cy Young (although, if the White Sox stay in first, it would probably be Chris Sale since he's never received an award and the award givers are nice like that). Verlander is the safe bet though, but I could see it go either way I guess (Sale's rate stats have been ridiculously good). In the NL, pitching has been unbelievable... Greinke, Strasburg, and Dickey would all be candidates right up there with or ahead of Sale and Verlander. Granted, AL probably has better hitters and whatnot, but the NL is pretty stacked for aces. I'm gonna go with Strasburg as NL Cy Young Award winner. It looks like the Nats will probably make the playoffs and most will point at Stephen as the key reason why if they do so. That said, Greinke looks to get more innings as well as Dickey so who knows?
*due to time constraints and retention of some semblance of sanity, I will only be looking at the top 5 pitchers by FIP in each league... dark horse candidates are Johnny Cueto (120 IP, 3.0 WAR) and David Price (111.2 IP, 3.28 xFIP)
Bonus Cardinal ace coverage
Just as important to the Cardinals as Wainwright is Chris Carpenter's replacement, LL. The Lynninator stats: 3.33 FIP, 3.41 ERA, 3.46 xFIP, 3.61 tERA, and 3.49 SIERA in a solid 103 IP. 3.46 averaged rate, .298 BABIP. weakness: a 3.15 BB/9
The Cards' other ace of course is Wagonmaker, or Waino, or A.D.A.M., or what have you. The opposite of a clubhouse cancer has turned what at times looked like a rough start into a great first half: 3.33 FIP, 4.56 ERA, 3.08 xFIP. What some call bad results others see as bad luck. In 102.2 IP, Wainwright has a .333 BABIP against and a 13.9% HR/FB ratio. Other rate stats: 4.12 tERA and 3.29 SIERA. Updated ZIPS projection: 3.27 FIP. Averaged rate: 3.676. weakness: bad luck, coming off Tommy John surgery
Perhaps the least flashy of Cardinals' starters is also the leader in innings pitched at 116.1 and leader in ERA. Laying to rest many critics claims, Lohse has been a very acceptable middle to back of the rotation starter at 3.74 FIP, 2.79 ERA, 4.16 xFIP, 4.28 tERA, 4.32 SIERA. Averaged rate: 3.858, more in line with his ZIPS projection. weakness: is perhaps his strength... .257 BABIP against, so his second half will not be as good results-wise
I was going to leave out Jake but then I realized two things: he has not been as bad as I thought he was and if I'm including Lohse, why not include Westbrook. FIP/ERA/xFIP/tERA/SIERA: 3.69/3.75/3.71/4.19/3.79. Averaged rate: 3.826. Outperforming projection: yes. Updated ZIPS projection: 3.84 FIP. Sustainable BABIP: yes. 105.2 IP. weakness: hard to find this year, but here goes... his WPA is negative, and he's, well, Jake Westbrook