The faces of both the new 913D2 (seen here) and the 913D3 prototypes features some unique changes to the graphics.

Bobby is not one to hold back, especially when he's ask to validate a new club's performance.  

Brendan takes a lash with his new prototype 913D3.

Stephanie Bezilla, Titleist's Director of Metalwood Product Development, is on hand this week at Congressional to lend support during seeding and provide product details on the new 913 prototypes. Here, she answers a question posed by Titleist Brand Ambassador…

A view of the prototype 913D2 in the play position.

Titleist Tour Rep Chris Tuten gives Titleist Brand Ambassador Bobby Gates more details about the new 913 driver.

Monday marked the official start to the tour seeding and performance validation for Titleist's new prototype 913D2 and 913D3 drivers.

Where there are new prototype drivers, there are also new prototype driver headcovers.

Titleist Brand Ambassador Brendan Steele, deep in discussion with Titleist Tour Reps Scott Cuppett (left) and Larry Bobka.

A close look at the sole of the prototype 913D2.