Outfielder J.D. Martinez presents a team jersey to President Trump during a ceremony on the South Lawn of the White House in Washington on May 9 at which Trump honored the 2018 World Series Champion Boston Red Sox. (Pablo Martinez Monsivais/AP)

There’s a particular subset of Donald Trump tweets in which he tries to take credit for things for which he obviously deserves no credit. This is different than that genre of tweets in which Trump claims, retroactively, to have been right about something, a prolific genre of its own.

Here, we’re talking about tweets like this one:

You will not be surprised to learn that the number of airline fatalities globally in 2017, the only year of Trump’s presidency to that point, was not a function of Trump. You will further not be surprised to learn that, when the number of fatalities rose in 2018, Trump did not mention any relationship to the news.

There’s a subset to this variety of tweet in which Trump claims credit for something happening while affecting a sort of tongue-in-cheek tone. Before he was president, for example, he used to tweet on occasion about how the New York Yankees would always win their baseball games when he attended. This, we discovered, was untrue; of the 13 games where we knew he’d attended, the Yankees won seven, slightly above half.

The idea, though, is that Trump’s magic touch extends beyond the business world (and now, the political world) to the world of sports. It’s akin to his insistence last year that his endorsement was winning race after race for Republicans — neglecting to mention that this effect only really worked in the Republican primaries. In the midterms last year, Trump again broke about even. But the point Trump wants to reinforce is that he’s always right and always successful, even indirectly. His occasional tongue-in-cheek-ish tone is simply a way to hedge his bets.

Monday morning, Trump again offered an example of this genre.

The president is entirely correct that, since visiting the White House last week, the Red Sox haven’t lost. Over the weekend, they took 3-of-3 against the Seattle Mariners, win after win after win.

How remarkable is this? Well, consider that this is only the, uh, 11th time this season that the Mariners have lost at least three games in a row. The Mariners are in third place in the AL West, with a record of 20-23. In other words, when teams play the Mariners, they usually win.

Congrats to the Red Sox, I guess.

But notice that Trump goes further: Other teams that have visited him at the White House have also “done very well.” Okay, fine. Let’s evaluate that claim.

We looked at the fates of eight teams that visited Trump after winning a national championship — plus two team that feuded with Trump and were disinvited, the Philadelphia Eagles and the Golden State Warriors.

Now, remember: These teams are there because they are very good. They won championships! The odds that they’re going to keep winning are pretty good compared to, say, the Seattle Mariners. So how’d these teams do in the first four games after visiting the White House? They went 27-12, a win record of 69 percent.

(Philip Bump/The Washington Post)

There are a lot of caveats. Most of those wins came against teams with losing records. Those involving NFL teams and college football teams came well after meeting Trump (or well after they were supposed to have met with him). That Clemson and Alabama went 8-0 after meeting Trump is unremarkable to the extent that championship-caliber college football teams often have relatively light early schedules. (Source: I went to Ohio State.)

For the Sox alone, there is an important caveat: The team’s manager, who might have more of an effect on the team’s performance than the president, skipped the White House visit. They are also the only team who won all of the games that followed within a few weeks of a Trump visit.

In the first four games after meeting (or not meeting) with Trump, here’s how these 10 teams fared:

  • First game: Won 7 of 10 times against opponents with an average win percentage of .410.
  • Second game: Won 7 of 10 times against opponents with an average win percentage of .490.
  • Third game: Won 8 of 10 times against opponents with an average win percentage of .550.
  • Fourth game: Won 5 of 9 times against opponents with an average win percentage of .390.

(We’re waiting to see the results of the Red Socks’ fourth game.)

But that’s over the short term. How’d they fare over the long term?

Each team made the playoffs in the following year. But only one of the 10 teams actually repeated as champion: The Warriors.

The lesson, then, is: If you want to win most of a four-game stretch, go meet with Trump, but you won’t win a championship. If you want to win a championship? Skip Trump and you’ve got 50 percent odds of repeating.

This is nonsense, of course. As is Trump’s bragging about his magic touch.