How do you explain Aaron Nola’s down season? Bad luck, for starters.

Let’s be clear: Aaron Nola didn’t have a good year.

Among 22 pitchers who worked enough innings to qualify for the National League ERA title, Nola ranked 20th with a 4.63 mark. He gave up 82 two-strike hits, most in the league and tied with Texas’ Jordan Lyles for the most in baseball. He yielded 26 home runs, 12 in two-strike counts, 11 with a runner on base, and 10 on his signature curveball. He completed at least seven innings in five of 32 starts and posted a 6.19 ERA over his last six starts.

Oh, and he was surpassed by Zack Wheeler as the Phillies’ No. 1 starter.

“I didn’t put the team in the best position to win as many times as I wanted to,” Nola said two weeks ago in Miami, during the final series of the season. “Obviously.”

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The Phillies expect more from Nola. Nola expects more from Nola. It’s easy to peg him as one of the primary culprits, with shortstop Didi Gregorius and regressive third baseman Alec Bohm, for the Phillies’ falling short of the postseason for the 10th year in a row.

But there is also a sense, not only among Phillies officials, that Nola didn’t pitch as poorly as it appeared. It isn’t only that opponents hit .309 against him on balls in play (.300 is considered average; in 2018, batters hit .258 against him on balls in play). His FIP — the acronym for “fielding independent pitching,” a measurement of runs allowed only through events that are within a pitcher’s control (homers, walks, hit by pitches) — was 3.37, 10th in the league and more than a run lower than his ERA.

Could it be, then, that Nola was almost as unlucky as he was ineffective?

“That’s absolutely part of his peripherals [numbers], for sure,” said one longtime scout from a rival NL team.

Nola, quiet with an aw-shucks personality, chuckled at the notion that serendipity wasn’t on his side. But the 28-year-old right-hander didn’t reject it either.

Few pitchers work ahead in the count more than Nola, who got to two strikes in 459 of 749 plate appearances (61.3%) against him. He conceded that he didn’t make enough good pitches in those situations to consistently reach his typical level of performance, even though he was fifth in the NL with 223 strikeouts. And other times, the right pitch yielded the wrong result. Opponents batted .186 against Nola after two strikes. But when they put the ball in the play in two-strike counts, they hit .338.

“You’re going to make good two-strike pitches, they’re going to get a hit; you’re going to make bad two-strike pitches, they’re going to get a hit,” Nola said. “You get bloop hits that fall in. The results are out of your hands. All I can control is getting that ball to where I want it.”

Late in the season, pitching coach Caleb Cotham put it this way: “There has been a good amount of times where he’s made a really good pitch and it’s been just enough where it’s right over the infield. It’s really tough to say, ‘Hey, you should’ve done something different,’ when you get that weak contact.”

But not all of Nola’s problems can be explained by misfortune.

The NL scout noted a rise in the rate of fly balls against Nola, from 17.5% in his breakout 2018 season, 20.7% in 2019, and 13.7% in the abbreviated 2020 season (when his strikeout rate soared to 33.2%) to 27% this year, and labeled the trend “concerning.”

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Nola’s home-run rate also jumped to 3.5%, the highest since his rookie season and greater than both his career average (2.8%) and the league average (3.2%).

“I think the ball was elevated a little more this year,” Nola said.

Indeed, Nola threw fewer sinkers than usual during the first half of the season, preferring instead to lean on his four-seam fastball. The scout wondered if Nola wasn’t trying to be more like Wheeler, who throws the four-seamer more than 40% of the time but also cranks it up to 97 mph compared to Nola’s 92-94 mph.

Another theory, floated by a second NL scout, was that Nola became unnecessarily experimental with a cutter. He mostly shelved the pitch through the middle of the season before picking it back up in September. But his initial flirtation with it may have created inconsistency in establishing his sinker and curveball.

Yet another NL scout speculated that Nola got away from the sinker, intentionally or subconsciously, because of the Phillies’ sieve-like infield defense. Nola’s ground-ball rate plummeted to 40.8%, a career low and down from 50.8% from 2016 to 2020. It raised some eyebrows, too, that his sinker usage skyrocketed from 10.8% over his first 24 starts to 22.3% in his last eight after Bohm was demoted to triple-A and replaced at third base by veteran utilitymen Ronald Torreyes and Freddy Galvis.

Coincidence? Entirely, according to Nola.

“It just wasn’t feeling as good, especially early in the year, middle of the year,” Nola said of the sinker. “I started throwing it a lot more probably my last 10 starts. It just felt better. You’ve got to go with what’s feeling good. If it’s not feeling that good, I’m not going to throw it that much.”

If anything, Nola believes the spikes in fly-ball and home-run rate were caused by flaws in his mechanics. Through the middle of the season, in particular, he said he wasn’t balanced over the rubber, leaving his arm to move too quickly or slowly relative to the rest of his body.

The result: “I was getting under the ball more than I want.”

Nola’s fastball had less backspin and tended to leak over the plate. His curveball, typically his best pitch, began to “pop out” of his hand and linger up in the strike zone.

“I had to tighten the delivery for a little while there,” he said.

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To get a better feel for his mechanics, Nola played catch from a mound instead of flat ground. He had hitters stand in on his bullpen sessions. He huddled with Cotham, his fifth pitching coach with the Phillies in five years.

“The curveball is slow enough to, when it does hang, guys have a little more time to react to it,” Nola said. “I feel like a lot of [the homers] came on curveballs right in the zone. Didn’t get those away enough. It’s always been one of my pitches and executing this year wasn’t as good as I want it to be.”

Nola’s default mode is always to prioritize his arm health. As long as he’s able to keep his arm in tip-top shape to make every start and the bullpen sessions in between, he believes he can get on a roll. And he remains among the most durable pitchers in baseball.

Even though he missed a July 11 start at Fenway Park because he went on the COVID-19 list as an unvaccinated close contact after Bohm tested positive, Nola is among eight pitchers to make at least 30 starts in each of the last three full seasons. Since 2018, he has made 111 starts, three more than any pitcher.

It’s a distinction that he wears proudly.

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But Nola was unable to get back on track in the second half of the season. Not fully, at least. He came within one out of a complete game July 25 in a 2-1 victory over the Atlanta Braves and racked up seven strikeouts in four scoreless innings of a rain-shortened start Aug. 10 against the Los Angeles Dodgers. He took a perfect game into the seventh inning Aug. 21 in San Diego only to give up a game-tying two-run homer to the Padres’ Jake Cronenworth in the ninth.

It begs the question of whether hitters, especially in the NL East, have grown overly familiar with Nola, who had a 5.01 ERA against the Braves, Marlins, New York Mets, and Washington Nationals. That may have been part of the motivation to fiddle with the cutter.

“I’ve got to start making a little more adjustments to especially those teams,” Nola said. “It’s a fine line. You know those guys as well as they know you. At the end of the day, it’s all about execution.”

A little luck couldn’t hurt, either.