Baseball can be a funky game. Pitchers we expected to be studs aren't performing as well, and some are wildly surpassing our expectations.

The great thing is that it's a long season, and between second-chance leagues post All-Star break, or just making up ground in your current leagues, you aren't dead in the water. Yet.

Let's examine four pitchers who could be primed for some negative regression in the second half. For each hurler, we'll show his average draft position (ADP) among pitchers in the NFBC and how that compares to where his first-half performance ranks among starting pitchers, per the ESPN Player Rater.

Luis Castillo, Cincinnati Reds

2019 NFBC Average Draft Position (ADP): 40
ESPN Player Rater: 8

Following a brilliant finish to his 2017 second half, Luis Castillo was the darling of 2018 drafters. And then he hit them with a thud.

But 2019 has been a different story altogether, as Castillo has been one of the best pitchers in baseball with a sparkling a 2.38 ERA and 28.8% strikeout rate over 106 innings pitched.

Unfortunately, things could come crashing down in the second half for the Cincinnati Reds righty. His 12.3% walk rate is the second-worst among the 78 qualified starters, and his 83.2% strand rate is the fourth-luckiest mark among that same group.

While Castillo has been fantastic, if he doesn't clean up that walk rate, the ERA could skyrocket.

Mike Minor, Texas Rangers

2019 NFBC Average Draft Position (ADP): 126
ESPN Player Rater: 11

During draft season, Mike Minor was basically a free space. Getting picked on average at pick 368 overall, he may have gone completely undrafted -- not bad for a guy currently functioning as an SP1.

Minor's late-round availability actually makes a ton of sense -- in 2018, the southpaw recorded a 4.27 skill-interactive ERA (SIERA), and that was driven by a 44.9% fly-ball rate coupled with a 20.6% strikeout rate.

Pegging Minor for regression makes sense when you consider that his current 2019 SIERA is worse this season at 4.41 -- but what's the driver? His walk rate has spiked to 8.7%, the highest mark of his career, and as we noted with Castillo, Minor's been a bit lucky with an 86.5% strand rate, the second-highest among qualified starters.

Minor's certainly been a blessing to fantasy staffs in the first half, but that 2.54 ERA is likely on the rise.

Justin Verlander

2019 NFBC Average Draft Position (ADP): 4
ESPN Player Rater: 2

One of fantasy's top-flight aces has been just that this season -- in a season marred by instability in pitching, Justin Verlander has rang the bell at every opportunity, posting a 2.98 ERA in the first half a whopping 31.5% strikeout rate.

So why be nervous? A few signs, actually. Verlander openly complained about the purported change in baseballs this year, and he's got a beef -- his 1.85 home runs per nine innings (HR/9) would easily be the worst mark of his career.

Unfortunately for Verlander, there's more to it than that. He's posted a silly 90.7% strand rate, and his 40.2% hard-hit rate allowed also blows away 2018's mark of 29.1%. Verlander's 15.0% soft-contact rate is down, too -- it would be his worst mark since his 2006 season as a member of the Detroit Tigers.

With an elite but declining strikeout rate, and an ugly batted-ball profile mixed in with an unsustainable strand rate, look for Verlander's ERA to spike.

Hyun-Jin Ryu, Los Angeles Dodgers

2019 NFBC Average Draft Position (ADP): 62
ESPN Player Rater: 3

Coming off a bumpy 2018 season derailed by injury, Hyun-jin Ryu of the Los Angeles Dodgers slid down draft boards, and if you drafted the lefty, you've been #blessed by some outstanding work in the first half of the season.

Ryu's 1.73 ERA so far has been built on a 2.4% walk rate -- which is actually a historic mark. Tracking the 787 qualified starting pitchers back to the 2010 season, Ryu's walk rate, over a full season, would be the third-lowest mark out of all of the pitchers.

For some context, it's also far better than Ryu himself has ever done. The lefty posted an 8.3% walk rate in 2017, and his 37.8% hard-hit rate, the second-highest mark of his career, doesn't play well with this microscopic ERA, either.

Long story short, don't expect Ryu to finish the year as a top-five starting pitcher unless his insane command and control remains for the rest of the year.