Entering play on Thursday, only seven pitchers have made at least five starts while striking out at least one-third of the batters they have faced: Gerrit Cole (41.3 percent), Max Scherzer (40.0), Robbie Ray (36.3), Justin Verlander (35.0), Patrick Corbin (34.5), James Paxton (34.0) and ... Caleb Smith (33.8)?!
Queue the music (sorry, I can't sing it for you, since this is print): "One of these things is not like the other ..."
Smith's hot start to the 2018 season has taken everyone by surprise, though with seasonal samples expanding to a size of relevance, he's now capturing much attention and was one of the most-added players of the past week (plus-29 percent in ESPN leagues). We'll also get our next opportunity to watch him pitch on Thursday night, when he'll battle an offense that has taken everyone by surprise, the Atlanta Braves, who currently lead the National League in runs scored.
Unfortunately, for all the excitement generated by Smith, I am not a long-term buyer and think he's a classic "juice-the-orange" guy. And while his control has been sharp enough in his past three starts to roll the dice on him again Thursday, it's conceivable that this is the night when the magic ends, considering the Braves enter with the majors' best team wOBA (.353) and lowest strikeout rate (17.6 percent of PAs) against lefties.
In Smith's defense, his slider has been solid and is largely behind his performance to date; his .155 wOBA allowed with his slider ranks 10th-best among 94 pitchers who have thrown at least 100 of them, and his 18.3 percent swinging-strike rate is a decent margin better than the league's average on sliders (16.7 percent). He has also earned positive run values, per FanGraphs, with both his four-seam fastball and changeup. Smith's above-average strikeout potential is the one thing that presents potential staying power.
The problems, however, are that Smith's fastball doesn't bring a lot of velocity (92.6 mph average) and his changeup lacks much in the way of movement. Looking at those pitches, the wide differential in velocity between them is probably behind his success (9 mph differential, as his changeup averages 83.6 mph). He's also an extreme fly ball pitcher, with a mere 32.5 percent ground ball rate (11th-lowest among 137 pitchers with at least five starts). Also, his .112 well-hit average allowed is slightly greater than the league average (.111), and he has a way-too-high 12.0 percent walk rate (11th-highest among the aforementioned group) . Smith's .257 batting average and .486 slugging percentage allowed to the 85 hitters he faced during spring training also suggest he has a good amount of regression due.
Since a lot of this is guesswork, my guess is that Smith is capitalizing upon his opponents' limited (or nonexistent) exposure to him, which makes more sense if you consider his 2018 schedule to date: Each of his seven opponents was facing him for the first time in the major leagues, and the one that hit him best was his team last season, the New York Yankees (April 16), who of the bunch presumably would've been the most familiar with him. My suspicion would therefore be that as opponents face him for the second and third times, they'll be readier for Smith, and that might exacerbate his shaky combination of mediocre control and a fly ball leaning.
Since Smith's success has only recently been catching fantasy managers' eyes, the prospects of "selling high" are slim to none. That's what makes him more of the chasing-streaks type hinted above, as he might have a few more outings in which he has the advantage over unfamiliar hitters. Plus, he does have decent enough stuff to be able to succeed against bottom-10 offenses and/or in Miami's spacious home ballpark. The sum might be only a borderline top-75 fantasy starting pitcher, though, and even now, I couldn't rank him that generously.
Just don't get cozy, and certainly don't "buy high."