The MLB season began again on Friday, and because it's mid-July, that means one thing: trades! Every team on the fringes of contention will try to patch up their holes to maintain a fleeting shot at October, while the rebuilding clubs gleefully extort as many prospects as they can in return. In 2016, though, it seems like not as many players — especially starting pitchers — will be made available. When SB Nation's Grant Brisbee broke down the sparse trade options back in June, he argued that the starters on the trading block amounted to "a seller’s market to an extreme I’m not sure we’ve seen before."

With that said, contenders can try to acquire one top-notch starter (as Brisbee noted): Rich Hill. Last September, the lefty dominated in a brief showing for the Red Sox, twirling four starts of 1.55-ERA, 2.66-DRA ball. That convinced the Athletics to ink him to a one-year deal, which he's since made good on: Through 76.0 innings, he's earned a 2.25 ERA and 2.51 DRA, each of them among the best in all of baseball. Notwithstanding a DL stint that prevented him from pitching in June, and a brief blister problem that pushed his start to today, the 36-year-old has garnered a lot of interest.

So what should contending teams know about Hill? For a breakdown of the changes that turned him from journeyman into ace, look here, or here, or just Google "Rich Hill comeback". I'd like to narrow in on two esoteric facets of his season to this point. If you want your team to burn down the farm to reel in Hill, you should probably get a better idea of the crazy stuff he's pulled off.

He's pounded the zone, and hitters haven't swung.

Think about the most fundamental decision in baseball: whether or not to swing. What makes the hitter determine this, in the infinitesimal amount of time that he has per pitch? I'm no baseball player myself — I really can't emphasize that enough — but I'd presume that the pitcher's zone tendencies have something to do with it. If I step in against someone who I know throws the ball over the plate, I'll probably expect to swing; on the flip side, facing a pitcher with control issues might make me more inclined to hold up.

This is all a poor way of saying, look at this graph:

Here, we see the 139 pitchers who have accumulated at least 60 innings this season, with their zone and swing rates, according to FanGraphs' PITCHf/x data. While the relationship between these two variables is pretty weak — the r-squared for this data set sits at an uninspiring .082 — you can still discern a vague positive trend. Most pitchers with high zone rates will have low swing rates, and vice versa.

Most, but not all. See the lonely dot up and to the left? As the subhead probably spoiled, that's Hill. Thus far in 2016, he's targeted the zone on 56.8 percent of his pitches and gotten a swing on 42.1 percent of said pitches. (Hill isn't the sole outlier on this graph; we encounter Zack Greinke in the lower right hand corner, and Bartolo Colon above and to the right of Hill. Those hurlers, however, aren't on the trading block, which means analyzing them wouldn't garner the clicks that Hill #content will.) Neither of these traits stands apart on its own. It's when they come together that they make for a dangerous — and rare — combination.

PITCHf/x dates back to 2008 (reliably). Since then, 2,298 pitchers have thrown at least 60 innings in an individual campaign. For each of these seasons, I adjusted the zone rate to the major-league averages*, yielding Zone%+. Hill's 56.8 percent zone rate translates to a 118 Zone%+, which makes him one of 189 pitchers in the sample with a zone rate 10 percent better than average. In other words, as stated previously, pounding the zone is not uncommon.

*The standard plus-metric methodology: Take the player's number, divide it by the average, and multiply by 100.

But how many of those pitchers have low swing rates as well? I also went ahead and created Swing%+ for that 2,309-pitcher sample. Take a look at the leader board for lowest adjusted swing rate:

Weighted by innings, the average Swing%+ for this 189-man group is 106. Just 24 of these pitchers have a below-average swing rate, period. What Hill has accomplished doesn't occur very often — he's duped his adversaries into a false sense of patience despite possessing superb control.

What explains this? If Hill had made only a few starts this season, we might attribute it to hesitance from his opponents — with an unknown on the mound, they may decide to play it safe and watch over the pitches he throws. That thinking might apply to Phelps, whom the Yankees traded to the Marlins prior to the 2015 season; National League hitters might not have known about his zone-pounding ways. And Hill still doesn't have that much exposure, so a lack of familiarity might account for some of it.

This theory can't cover everyone, though. Badenhop has done this his entire career, albeit to a smaller degree — he has a lifetime zone rate of 51.5 percent and a swing rate of 41.2 percent, and those come over 512.1 innings of work. Every once in a while, a hurler can maintain this paradoxical formula, some way or another. Maybe the secret stuff that resurrected Hill's career has also made him super deceptive. The safest bet would probably be some regression, but it might not go away entirely.

He's lost a ton of strikes.

So with such a high zone rate, and a low swing rate, Hill has probably collected a boatload of called strikes, right? According to Baseball-Reference, 22.0 percent of his pitches this season have gone for a strike this season. While that's one of the better marks in the majors, it nevertheless trails pitchers like Aaron Nola (24.3 percent) and Kyle Hendricks (22.7 percent), among others. Shouldn't Hill have done better than this?

This is where the second fact, also revealed by the subhead, comes in. Since we have zone rates and O-Swing rates, we can create an expected strike rate metric**. This won't include intentional balls, as PITCHf/x data doesn't track those; we'll therefore compare it to B-R's strike rate data, which similarly focuses on intended pitches. This fairly simple methodology gives us a sense of which pitchers have gained, or lost, strikes.

**Here, you multiply (1-Zone%) by (1-O-Swing%), to get the expected ball rate, then subtract that from 1.

About those lost strikes...Returning to the 2016 season and the aforementioned 139-man sample, we see that one arm in particular has gotten some bad breaks:

Yup — Hill has underperformed his peripherals more than any other pitcher with 60+ innings this season. His expected strike rate ranks him 11th in that sample; he drops to 63rd when it comes to actual strikes. This has unsurprisingly hurt him when it comes to bases on balls: He's posted an uninspiring 9.0 percent walk rate to this point. With more calls going his way, that mark would deflate in a hurry.

In and of itself, this isn't especially odd. The short end of the framing stick has to go to someone. It just seems peculiar that Hill, of all pitchers, should struggle like this. For one thing, his catcher — Stephen Vogt, who's caught all 76.0 of his innings this season — hasn't done that badly with receiving. Out of the 64 big-league catchers with at least 1,000 framing chances this year, Vogt's -.011 CSAA is tied for 46th, per Baseball Prospectus. That obviously leaves something to be desired, but still, 16 other backstops have fared worse (including Vogt's teammate, Josh Phegley, who checks in at a -.020 CSAA).

More importantly, Hill has helped his own cause. He's paired his control with impressive command, placing 30.2 percent of his pitches on the edges of the strike zone (via Bill Petti's data). Only two other 1,000-pitch pitchers have done better: Colon, at 31.4 percent; and Mike Leake, at 30.2 percent. Even with the framing incompetency, Hill has tried his damnedest to get strikes. Why, then, hasn't he netted his fair share?

In addition to my lack of hitting experience, I'm also very much not a pitcher, so this may be off base. With that said, the movement on Hill's offerings stands out to me as a possible cause. For the most part, Hill throws two pitches: a four-seamer and a curveball. Each of those has a ton of run — the former ranks seventh in the majors with 8.9 inches of horizontal movement, and the latter comes in at fifth with 8.6 inches. Perhaps the darting bite on those pitches makes them harder for catchers to present, or for umpires to judge.

Or, alternatively, Hill may simply be unlucky. 76.0 innings doesn't make for a large sample, and as Hill gets more action, he'll probably see his peripherals match his results. Moving on to another team, and teaming up with a skilled catcher, would only help. If he can progress in this regard while with the Athletics, he'll lower his walk rate and improve his trade stock; if it takes until a trade for it to reverse course, it'll just aid the new team.

When the month of July draws to a close, Rich Hill most likely won't wear the Oakland green-and-yellow. Everyone from the Rangers to the Orioles to the Red Sox wants to bring him in, and one of them should eventually outbid the others. After that happens, the two crazy tricks that have brought him here — one good, one bad — won't necessarily continue. Like Hill's success to this point, though, they're real, they're weird, and nothing can change that.

. . .

All statistics as of Sunday, July 17th.

Ryan Romano is a contributing editor for Beyond the Box Score. He also writes about the Orioles on Camden Depot and MASN Sports, and about the Brewers on BP Milwaukee.