Bowler Ratings


Bowler ratings are from 1 to 10 in order of Stroker (ST), Tweener (TW), Cranker (CR)

Note: Ratings are only available to our premium members.

General Info

Reviewed:April 2022
Coverstock Specs
Name:ACT 3.0 Solid
Type:Reactive Solid
Box Finish:500 / 2000 SiaAir
Color:Navy / Purple / Sky
Core Specs
Name:Portal X
Int. Diff:0.015

For details on our standard test layouts, please click here.

The Defender brings a new core shape and a new coverstock to the Brunswick Pro Performance line. The Activator Composite Technology cover is updated to the ACT 3.0 Solid version for this ball. It is finished with 500 and 2000 SiaAir, which allows the Defender to dig into the oil. The new Portal X core shape is based on the Portal core from the Prism line, with a slightly higher RG and total differential compared to the original design. The Defender is built for oil, and it handles it well.

Cranker was very comfortable with the Defender on the heavy oil pattern. He played 2-and-2 right compared to the Quantum Evo Solid on the fresh, seeing a sharper change of direction downlane. The extra angle was very useful later in the session after the pattern transitioned. He could move left to find more oil in the front to keep the ball strong in the pocket when smoother offerings like the Knock Out Black and Blue were losing a little more energy. The box finish was best on both the

Brunswick Defender Comparisons

Click below to see a comparison table of each pair of bowling balls shown:

To compare the Brunswick Defender to any other bowling ball(s), please use our Bowling Ball Comparison tool.

Additional Brunswick Defender Resources

Click here to visit Brunswick's website to read the manufacturer-supplied information on this ball. Also, see below for the manufacturer-produced promotional video for this ball.

Please remember that our reviews are solely based on our own testing and that you may sometimes find differences between our comments and ratings and the manufacturer's claims. Links to these manufacturer resources are provided here strictly for convenience purposes.

The BTM Ball Testing Team

About The BTM Ball Testing Team

The BTM Ball Testing Team is led by Eric Martinez. Our team of three testers has thrown and reviewed hundreds of bowling balls for Bowling This Month. When not testing balls for BTM, Eric owns and operates University Pro Shop in San Antonio, TX and he is an avid competitive bowler. Click here to learn more about how we test and review bowling balls.