While I am not going to sit here and debate for or against Cole getting a rating bump, I do want to point out that you need to be careful using stats such as wins and ERA (again, I am not sure what SCEA uses). Especially wins. I would argue that pitcher wins is the most overrated and awful stat to use in sports.
Anyway, I am not trying to attack you or necessarily debunk anything you are saying, but I think this is an excellent example to use to point out why a stat like ERA should never be used by itself to evaluate or rate any pitcher.
So, Cole has an ERA of 1.71 on the season through 13 starts (84 IP). When I see that type of ERA, I want to either make it a stronger case, or explain why it might be so low. Taking a look, his xFIP is 2.68 with a SIERA of 2.70. Those two numbers are actually excellent, but since it is still early in the season, they are tied for 8th among starting pitchers. Additionally, the ERA-xFIP is -.65, which is the 21st highest (or lowest) among starting pitchers. This is signaling that there is inconsistencies in his statistics and that there is something going on (either getting lucky, pitching in pitcher friendly parks, playing poor quality opponents, or all three). Now keep in mind that Cole is a power pitcher and a strikeout pitcher which means his SIERA and xFIP are going to also be more favorable.
Anyway, when you look further into the reason for the ERA-xFIP or ERA-SIERA, you notice a couple of things. First of all, his HR/FB% is one of the lowest in MLB at 7.1%. The average is between 9-10% and this is not a stat that stays in favor of pitchers over the course of any amount of time. This is a regression to the mean statistic meaning that either he is playing in pitcher friendly parks, is getting lucky, or is facing poor opponents. If you want to look quickly at the other side of the spectrum, Felix has a FB/HR% currently of 21.3%, which is why his xFIP is quite a bit lower than his ERA. It is factoring in that he won't give up 21.3% FB/HR all season just like Cole will most likely not stay with the 7.1% (last year it was 9.4% and the season before 8.1%).
Yes, that is a fairly minor difference, but it does make a difference. Next then you have to look into the quality of opponent and parks that he has been pitching in.
You mentioned his 5 most recent starts. They were Phili, @Atlanta, @SFG, Miami, NYM. Now, to keep this brief and simple I am going to use wRC+ as a statistic for his opponents hitting. It is a well rounded stat that includes league averages and park factors. This article explains it in more detail (
wRC+ Explained).
Okay so his recent opponents are currently 30th (Phili), 27th (Marlins), 20th (Braves), 17th (Mets), and 4th (Giants). Nice work for him against the Giants even though it was in a pitcher friendly park. Now looking over his season, he also has another start against Phili, one against Milwaukee (29th in hitting), Arizona (19th), Cinci (16th) twice, Chicago (18th) twice, and Detroit (3rd) once.
So that means out of his 13 starts this year, only 2 of them have been against teams that are better than 16th in hitting! So, that definitely helps explains his very low (or high, however you want to put it) ERA-xFIP or ERA-SIERA stat and is also a very very good reason and example of why stats like ERA by themselves should absolutely never be used to rate or evaluate a pitcher.
Again, I am not trying to attack you or even really debate whether or not he should get a rating boost (I could see a slight one). I just wanted to use your example as to why standard statistics such as ERA are not meant to be used by themselves.
EDIT: I will add links to brief explanations of some of the advanced stats that I mentioned incase anyone is confused:
xFIP
SIERA
wRC+
HR/FB% (This one does a good job of explaining how it is a regression to the mean stat)
This Article goes into further detail about why ERA is a bad stat to use by itself