Suits: R-B4 - another silly reference or am I missing something?

disclaimer: the pics have nothing to do with the dialog in question

http://transcripts.foreverdreaming.org/viewtopic.php?f=189&t=33919

Jessica: Harvey, my advice is to give a big piece of new business to the person least likely to let anything go.

Harvey: Louis.

J: Nine times outta ten.

H: I can't just manufacture that overnight.

J: Harvey, do you remember that time we poached Trotter Systems from Zane?

H: You gotta be $h1tting me. That was a prearranged deal? I worked my a$$ off to get Trotter.

J: You did. And you completely forgot that you were pissed at me about some bull$hit neither one of us can remember anymore.

H: Rook to bishop four.

J: Exactly. 

Is there some famous deflection in a game with R-B4?  Or did they just make it up to sound clever?

Eh... maybe.

I don't know anything about this show, but my impression is they're trying to spice up this exposition. "Remember that time we formed a bond during an event?" is really lazy (and boring) writing. Throwing in a nonsense line about rook to bishop 4 engages the viewer, making them think "what the hell does that mean? I wonder what the experience they're referencing was like" and so it's not as boring anymore.

Like adding extra frosting to a bad tasting cake

Just my impression though.

chess references all over.

denzel: "this $hit's chess it ain'tcheckers"

jessica: "this is isn't chess, it's dominos" (couldn't find a clip in English - but you can hear bobby fischer being mentioned)

Wait a moment, could it be B-R4 instead?

Now that was some serious deflection.

I am here for some reason , i search what jessica meaning for "rook to bishop four"