This is the time of year that most fantasy owners decide to make some moves and shake up their roster. Perhaps there is an owner in your league who is fed up with a certain player that they expected more out of or there is a player on your team that has struggled thus far and you are considering trading him. The key to evaluating these situations is determining whether luck has played a factor in the statistics thus far.
CC's average fastball velocity is down 3+ MPH from 2011. This has resulted in him becoming much more hittable. His GB% is way down and his HR/FB is the highest of his career. Time will tell whether Sabathia can make some adjustments and regain some of his lost velocity. I suggest selling Sabathia and definitely won't be buying him in any of my leagues.
Matt Moore should be sold high by anyone not in a keeper league. He is 8-0 with a 2.21 ERA but his FIP, xFIP, and SIERA are all over 4. Moore's .204 BABIP against is evidence that he has been very lucky and I expect him to have around a 3.75 ERA from here on out.
Dickey's velocity is down a bit and his fastball has resulted in a .333 average with 4 HR for hitters. His BB/9 is double what it was last season. This has resulted in hitters being able to sit on his fastball when he gets into a bad count. Dickey's underlying values confirm that his struggles are legit. He has a 4.85 ERA, 4.88 FIP, and 4.44 xFIP. Don't buy on Dickey.
Scherzer has pitched tremendously this season. He has pitched so well that his 3.42 ERA is actually evidence that he has been unlucky. Scherzer's FIP, xFIP, and SIERA are all under 3. There's a strong possibility that Scherzer puts up a sub-3 ERA for the rest of the season with more than a K per inning and plenty of wins. If you can get a decent price on him then why not buy?
Verlander's average fastball velocity is down a little for the season but it's his .358 BABIP against that has led to his 3.66 ERA. His FIP is just 2.5 while his xFIP and SIERA are slightly over 3. Play up Verlander's lost velocity in your negotiations and you might get yourself a bargain.
Cain has a 5 ERA and 1.19 WHIP. It doesn't take a rocket scientist to figure out that something doesn't add up here. Cain's HR/FB is more than double his career average. For a pitcher who plays his home games in a pitcher's park this is a bit surprising but there's little reason not to think Cain's ERA will get lower and lower with each and every start.