My box score says only 7 unearned runs. But five errors, all on bad throws. What did Casey Stengal say back in the early Mets years when Marvelous Marv Throneberry ("stone hands") played 1b? "Can't anybody out there play this game?"
In his last 10 appearances, Kelly has given up 8 runs in 10 innings. His 100 mph fastball ain't enough when the other team can sit on it knowing he can't throw a curve or other breaking ball for a strike.
The Sox team ERA has dropped back to 2d best in the AL maybe because of an over-reliance on fastballs along with an inability to hit spots, especially with breaking balls. At his best, Uehara couldn't throw a fast ball over 90 mph for love nor money. But he had that great splitter, terrific command of his pitches, and total confidence when he threw a pitch. Because of that he seemed to be able to throw that nothing fastball with impunity. That's pitching.
Sale has a darn good slider and pretty good control of it too, but the problem is that like 80% of the guys he faces are righties, which reduces the effectiveness of that slider. He has a decent changeup, but my guess is that, even against righty batters, he uses it about 1/3 as often as the slider. And, of course, he has the terrific fastball that he still throw 50% of the time.
Porcello's basic problem, I think (and will await someone else's analysis), is that he cannot consistently keep the ball low in the strike zone in an era when smarter pitchers have realized that that ability alone is more important than having great stuff which Porcello also does not have.
Those shifts, which are having a pronounced effect on hitters, have caused some of them to want to get the ball in the air over the shifts. This in turn makes controlling the lower part of the strike zone ever more important to enable those shifts to be effective. I think the Sox pitching coach has done a good job this year, but not with Porcello. Or maybe Porcello is dumb as a post.