Every baseball executive understood by mid-June that Washington general manager Mike Rizzo needed bullpen help -- again -- to help plug the gap at closer. But Rizzo’s choices were far less than perfect, certainly less attractive than in 2016 when he talked about deals involving Aroldis Chapman and Andrew Miller before trading for Mark Melancon -- all elite closers.

The biggest name available in this year’s market is Zach Britton, and because of an ongoing lawsuit between the Orioles and Nationals, the odds of a deal between Baltimore and Washington involving such a prominent player is probably close to zero.

So it came as no surprise to some of Rizzo’s peers that he eventually turned to Oakland to make a deal for bullpen help. He's made a lot of trades with Billy Beane, the head of the Athletics’ baseball operations -- almost a dozen trades involving Gio Gonzalez, Josh Willingham, Yunel Escobar, Tyler Clippard and others. For Rizzo and Beane, deal-making with each other seems like comfort food.

This time of year, needs and wants are just a couple of factors that shape deals leading up to the trade deadline. The working relationships between the executives making the deals are another -- and an incredibly underrated part of what goes on this time of year. Some rival execs can’t stand each other; some execs are friends and can make deals together; and some execs are friends and yet can’t seem to finish deals.

With that in mind, here are executive matchups worth watching over the next six days.

Andrew Friedman, head of baseball operations for the Dodgers, and Texas GM Jon Daniels

Dating back to the years when Friedman ran the Rays, the two have had a lot of discussions but no deals of significance. They executed just three minor deals.

Friends of both have speculated for years that the negotiation styles of the two are so similar that it probably makes deal-making more difficult, like two brothers using the same strategy in a board game.

This is noteworthy in a week in which the Rangers are listening to offers for Yu Darvish leading up to the trade deadline, and the Dodgers’ interest in adding a starting pitcher could be nudged by sudden uncertainty about Clayton Kershaw. Daniels has a player whom Friedman could certainly use in the weeks ahead.

There is an X factor. Farhan Zaidi is the Dodgers’ general manager, working under Friedman, and he is the person dealing head-to-head with Daniels. It could well be that the Dodgers don’t finish a trade for Darvish because they’re not interested in paying the asking price.

The Athletics and the Yankees

Beane has turned over his roster repeatedly, and the Yankees have been serious buyers in almost every year of Brian Cashman’s tenure as general manager -- and yet the two teams have virtually no trade history since 2003. The two teams have made one minor deal over the past 14 years.

Right now the Yankees and Athletics would seem to match in a lot of ways. The Yankees were in the bidding for Jose Quintana and could use a controllable starting pitcher like Sonny Gray. They're also looking for a left-handed-hitting first baseman and would seem to be among the very few suitors who might consider a deal for Yonder Alonso. Oakland is looking for prospects, and the Yankees have a deep stock of young players from which the Athletics could choose.

They could strike a deal that would have major impact for both teams. But they rarely do.

The Cubs and the Rangers

When Theo Epstein was with the Red Sox, he executed some notable deals with Daniels -- swaps involving Eric Gagne, Jarrod Saltalamacchia and others, and that has continued since Epstein and Jed Hoyer took over the Cubs. Just before the deadline in 2012, Epstein swapped Ryan Dempster to Texas, sending Kyle Hendricks and another minor leaguer to the Cubs, and the next year, he sent Matt Garza to the Rangers in a deal that netted Carl Edwards Jr. for Chicago.

The Cubs are among the teams that could be looking at Darvish. Could that history help? We’ll see.

The Dodgers and the Athletics

About a decade passed without a deal between these two longstanding franchises, from 2005 and 2015, but that has changed since Friedman -- and Zaidi, who used to work for Beane -- took over the Dodgers. They’ve made five trades over the past three years, including the big deal of Rich Hill and Josh Reddick last summer. If the Dodgers have interest in trading for Gray, that history could serve as a platform for conversations.