Drew Smyly probably isn't as good as he's shown since joining the Rays. Granted, you shouldn't put anything past their coaching staff -- Alex Cobb, Chris Archer and Jake Odorizzi all appear well on their way to maximizing their talents -- but in his last four starts, Smyly has been as good as the man he was traded for, perennial Cy Young contender David Price. No transformation is that sudden.
The most telling number for me is that one that falls well short of Price's standards: During that four-start stretch, Smyly has averaged 6.7 strikeouts per nine innings. And yet he's allowed 11 hits in 30 2/3 innings. The result is an impossibly low .111 BABIP.
Of course, one look at his 0.88 ERA during that four-start stretch would tell you it's something he can't sustain, so maybe I'm going overboard digging into the advanced numbers there. My point is this: He's good, but with middle-of-the-road strikeout ability and an occasional vulnerability to home runs, I don't see him becoming start-him-every-week good.
In a relief pitcher spot in a points league, maybe, but otherwise, keep an eye on the matchups and weigh your alternatives.