Through the first half of the season, Aaron Judge was baseball’s version of a perfect hitter.

The New York Yankees rookie boasted a .329 average with a 1.139 OPS and 30 home runs heading into the All-Star break. He could do no wrong at the plate, right through the Home Run Derby, which he won with an amazing performance.

But baseball is a game of adjustments. And the league has since adjusted to Judge.

The right fielder is struggling in the second half, hitting .182 through Monday's games, with a .710 OPS and five home runs in 22 games.

So, what happened? Let's take a look at how the league has adjusted to Judge.

A lot more high heat

One of the biggest adjustments pitchers have made against the rookie in the second half is throwing more fastballs and targeting them out of the strike zone. They've also pitched him higher in the zone and above the zone.

Judge went from seeing pitches regularly over the middle of the plate to pitches that are regularly up around his eyes. He's often obliged by swinging at those pitches with highly unfavorable results.

Slider placement

Pitchers are throwing sliders more often to Judge as well -- 28 percent of the time compared to 22 percent prior to the All-Star break. They're locating them better, as the heat map below shows.

Judge has seen 119 sliders in the second half, has swung at 56 and missed 36. He has no hits and 20 outs against them.

This was bound to happen

What has happened to Judge is not surprising. His paces in the first half were otherworldly, after all.

Judge had a .426 batting average on balls in play (BABIP) in the first half of the season. If maintained for a full season, that would have been the highest BABIP in the live ball era (since 1920), breaking the mark of .423 set by Babe Ruth in 1923. The last player to be within 15 points of Ruth did so 40 years ago (Hall-of-Famer Rod Carew, .408 for the 1977 Twins).

His BABIP since the All-Star break is .237. What caused this decline?

Judge's ground ball rate and line-drive rate are down 8 and 7 percentage points, respectively. His fly ball rate is up 16 percentage points. Fly balls are the toughest batted balls on which to get hits.

Also of note: Judge's rate of home runs per fly ball at the All-Star break (42 percent) would also have been the highest over a full season since the stat first became available in 2002.

Only two players have managed even a 32 percent rate (Jim Thome in 2001 and Ryan Howard in 2006).

Judge's fly balls averaged 100.3 mph in the first half. They're averaging 95.5 in the second half.

Another indication of Judge not squaring balls up as well as he had been: In the first half, he slugged a best-in-the-majors 1.056 against "mistake pitches" (pitches over the middle-third of the plate both height-wise and width-wise). That was 283 points better than the next-best player (George Springer).

Judge's slugging percentage on those pitches since the break is .500, which ranks 78th. In other words, opponents are pitching him smarter and better.

Now it's up to him to adjust.