The Mets' offense is, by any definition, on fire. In May, they scored 168 runs, tied for the third most in any month in team history. They had the second-highest batting average in the Majors, sure, but also the third-highest slugging percentage. After an April where they had baseball’s weakest hard-hit rate, they dialed that all the way up to 12th best in May.

That, if you ask most Mets fans, would be due to new manager Buck Showalter, or new hitting coach Eric Chavez, or just putting the ball in play, or the multitude of offseason lineup additions they made, and that’s probably all correct to varying degrees. What they’re doing is being relentless. They’re putting pressure on opposing defenses. The Mets have the fourth-lowest strikeout rate in the Majors; they have, by a large margin, the most infield hits in the game. Only the Dodgers turn more of their runners into runs.

In a baseball season where hitting for power in the air offers less return than you’re used to, maybe there’s merit to leaning into the older-school ways. After all, when they rallied for seven runs in the ninth to stage a comeback against Philadelphia on May 5, only two of them came on a home run. When they scored a dozen runs on 18 hits against the Giants on May 24, the same thing: only two runs came in on a homer.

Yet there’s one thing that still hasn’t quite added up, which is that – before this recent power-hitting run, anyway – it was hard to buy fully into New York’s “just put the ball in play” style of offense as being the primary cause for success when other teams who have similarly low strikeout rates, like the Royals, Nationals, and White Sox, have been some of baseball’s weakest run scorers. It can’t just be that, not when Kansas City has already fired its hitting coach due to underperformance.

But against the Nationals, and before that the Phillies, and before that the Giants and the Rockies, teams that aren't exactly known for their defense, it began to make more sense. Against defenses that have an aversion to competent fielding, maybe just putting the ball in play, any ball in play, really does make sense. After all, when those opposing fielders are giving you gifts like this, and this, and this, and this, you realize that striking out gets the iron gloves on the other side off the hook.

And that, really, is when it hit us. The last four teams the Mets have played are the Rockies, Giants, Phillies and Nationals.

The four weakest defensive teams in baseball? According to Statcast metrics: the Rockies, Giants, Phillies and Nationals.

You saw it, repeatedly, in Wednesday's victory over the Nationals:

It’s not just the last four series, either. The Mets have played the Phillies a dozen times already, and the Nationals 10. Throw in the 10 additional games against the Rockies and Giants, and that quartet accounts for 32 of the 52 games the Mets have played – or 62%.

Taken together, when the Mets have been hitting, the defenses they’ve seen against them have been baseball’s weakest, by a large margin, and that’s a metric that looks at everything from the fielder’s point of view, not the exit velocity and launch angle of the ball. (That is: how far, in how much time, in what direction does the fielder have to go?) It’s a gap of nearly 40 Outs Above Average between the team facing the toughest fielders, the Reds.

All of which leads to an extremely interesting chicken-or-the-egg question. Are the Mets finding hits (baseball’s second-highest batting average on balls in play) because they’re facing defenses completely incapable of containing them? (Those four clubs have allowed the four highest BABIP marks.)

Or: Is that the wrong way to look at it? The Mets are not indifferent observers here, of course. Are those four defenses struggling so badly because they’ve had to face so much persistent Mets hitting? It’s something of an important question as the Mets start a road trip against the Dodgers that then moves on to include the Padres and Angels – two of baseball’s best defenses. They won’t get the pleasure of facing the Phillies again until August.

There are two easy ways to test this, of course. The Mets have played other teams this year; they’ve seen the Mariners and Braves once apiece, and the D-backs and Cardinals twice. Those teams range from defensively poor (Atlanta) to excellent (Arizona); we can see what the Mets have been able to accomplish against this group as compared to The Big Bad Four.

Then, we can do the same for the Rockies, Giants, Phillies and Nationals. What does it look like when they’re not playing the Mets?

1) When the Mets are playing other teams

Let’s start with simplicity. The Mets have played 32 games against the four teams that can’t field. They’ve played 20 games against the other four teams. At the highest level: Are there more hits? Do they score more?

Well, yeah.

20 games against ARI, ATL, SEA, STL

• .282 BABIP
• .713 OPS
• 4.5 runs per game
• 0.9 HR per game

32 games against COL, PHI, SF, WSH

• .335 BABIP
• .770 OPS
• 5.6 runs per game
• 0.9 HR per game

The differences are stark. Against teams that can’t field, the Mets are scoring an extra run per game, without the benefit of more home runs. A .335 BABIP – that’s batting average on balls in play, or how often non-homer balls become hits – would be the highest in the game over a full season. A .282 would be 23rd. There are 60 extra points of OPS in here, too, which is probably a little about poor pitching as well as poor fielding. It’s a big deal.

It’s not about strikeouts, which were actually higher (20%) against the four bad fielding teams than against the other four (18%).

It’s clear they’re being helped by, well, this …

and this ...

… but, as we said, they’re hardly disinterested observers who have no role in this. Aside from the fact that putting any ball in play challenges those weak defenses, the Mets have simply been hitting the ball harder, and better, and more often.

And, also, they're doing it against teams that do not field baseballs. Against the four teams that absolutely cannot field, the Mets have a 39% hard-hit rate; against the other four, it’s 34%. So in terms of the runs on the board, it’s both things. They have played a lot of truly, deeply terrible defenses – but it’s also that the Mets have put those other teams in a position to fail.

2) When the poor fielding teams aren't playing the Mets

Forget the Mets, for a moment, and focus on their opponents. What do the defensive metrics look like when they’re playing the Mets as opposed to when they aren’t? This can help us learn a little more about how responsible the Mets might be for this.

The Phillies … have a minus-20 OAA overall, which is -4 against the Mets and -16 against all other teams. That’s bad all around; you can see it in their BABIP too, which shows no better or worse against the Mets than anyone else.

The Nationals … have a minus-17 OAA overall, which is -4 against the Mets and -13 against all other teams. Similar to the Phillies, it’s just a bad defensive unit regardless of the opponent.

The Rockies … have a minus-17 OAA overall, which is just -1 against the Mets and -16 against all other teams. Same story here; it’s not really a Mets issue.

The Giants … have a minus-16 OAA overall, which is somehow -10 against the Mets and -6 against all other teams, which is just unbelievable, really.

Then again, the Mets posted 78 hits in just 7 games against the Giants. (They had not one game with 18 hits, but two. The Giants committed zero errors, which doesn't mean they made no mistakes; it means they weren't good enough to commit errors.) By comparison, the Padres managed just 54 hits in six games against the Giants. ("You induce weak contact and they get rewarded for it," Giants pitcher Alex Cobb said. "I try not to get too frustrated. I try to keep that inside, but there were a couple tonight that I would have liked to be outs.”)

It’s clear that whatever happened against the Giants had a lot to do with the Mets. It’s less clear against the other three clubs.

So: Why is it working for the Mets in a way that it’s not working for, say, Kansas City? It’s a bit about line drives – only three teams have a weaker line drive rate than the Royals. It’s a bit about home runs – only three teams have hit fewer than the Royals. The Mets, especially recently, are hitting the ball often and well, in a way that the Royals are not. And, also, it’s a bit about not getting to play defenses quite like this.

The answer, as almost always is the case, is that multiple things can be true. The Mets' offense has been fantastic. They’ve also benefited by playing some of baseball’s weakest defenses, ones they were well-positioned to take advantage of.

The Mets are making their own luck. They’re pressing the issue. That’s entirely about them, and no one else. At the same time, they’ve had some help, which they’re likely to get less of over the next few weeks. That makes this upcoming road trip the truest test yet of how real the 2022 Mets offense might be.