Robotic testing confirmed there’s an uptick in tighter spin rates across the entire face, especially in the high toe section. The result is a tighter carry distance delta — in relation to center face impact — for one of the most common misses.
Innovative materials
The faces in the TSR line are constructed with ATI-425, which offers distinct advantages. This proprietary material offers 30 percent higher ductility, along with higher yield and tensile strength, which allows engineers to push manufacturing to higher tolerances for face thickness.
Reliability
Don’t fixate on distance with TSR. What makes this driver better than TSi is improved launch, spin and carry characteristics across all three driver models.
The TSR1 roughly 40 grams lighter than a standard driver making it the lightest among the TSR models.
Slow/Moderate Swing Speeds
The TSR1 is designed for slower to moderate swing speeds who want to pick up more distance (and launch) without making significant modifications to their swing.
Increased Club Speed
A new face and aerodynamic shape led to an increase of 1.5 mph more club speed during robotic testing, which translates to an additional 0.75 mph of ball speed.
The TSR2 has been re-engineered from the inside out to deliver more ball speed, stability and a look that fits more in line with the rest of the TSR series.
Improved Aerodynamics
The new TSR2 has adopted a more natural pear shape, like its TSR3 brother, which checks boxes for looks and also helps with aerodynamics.
Adjustability
In the back of the club, the adjustable sure-fit weight has been moved from the sole to the rear skirt so even with the slightly smaller front-to-back shape, the driver’s MOI still has been increased over the previous model.
The TSR3 follows a similar path of the improvements to the TSR2, thanks to a newly designed face insert and a subtly reshaped skirt and sole for better aerodynamics.
Adjustability
The rear weight of the sure fit track has been adjusted to move it more to the perimeter — same shape, higher MOI, more stability, more consistent ball speeds means improvements in every category.
New Face Design
A newly designed variable thickness face structure expands the COR area away from the middle of the face and helps the driver transfer more energy, leading to more ball speed on mishits.
The TSR4 is a true specialty club in the fitting space designed to offer reduced spin for players that have swing dynamics that make it harder to create ideal launch conditions.
Compact Design
The TSR4 also offers a smaller head profile. At 430cc, it’s one of few sub-460cc drivers on the market.
Adjustability
The interchangeable forward and rear weights allow the driver to offer the lowest spin head in the forward position, and when reversed the TSR4 becomes a smaller and slightly more workable version of the TSR3: still low spin but not too low that mishits become unmanageable.
As a quick synopsis, the TSR drivers build on the previous success of the TSi and TS series before that, of offering models to fit golfers of all skill levels and clubhead speeds. For the engineering team at Titleist, the message from the top down was clear: “Don’t mess up a great thing!”
To better explain the face material, ATI-425 is manufactured in the United States by Allegheny Technologies Incorporated (ATI), in Pittsburgh, and offers distinct advantages to conventional titanium used in golf. This proprietary material offers 30 percent higher ductility, along with higher yield and tensile strength, which is a complicated way of saying it allows engineers to push manufacturing to higher tolerances for face thickness.
With two more years of refinement and testing since the launch of the TSi, engineers have again saved more weight from the face to be positioned around the head to create stability without ever sacrificing durability.
Consistent Spin 
