Bowler Ratings


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

General Info

Name:Guru Mighty
Reviewed:February 2015
Coverstock Specs
Type:Reactive Hybrid
Box Finish:500 / 4000 SiaAir
Color:Navy Solid / Emerald Green Pearl
Core Specs
Int. Diff:0.018

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

The Radical Guru Mighty is the follow-up release to last year’s popular Guru.  It uses the same asymmetrical weight block that was found in the original. The Mighty Guru differs from the original in that it has a hybrid coverstock and a smoother 4000 SiaAir box finish, whereas the Guru had a solid cover and a 1500 SiaAir box finish. The Mighty Guru offers more length and back end reaction than the first Guru, but it still manages to provide a big amount of total hook.

Just like with the original Guru, we had the best reaction with this ball on our heavy test pattern. All three testers were a just a few boards farther left with their feet than they were with the Guru and they were seeing more motion at the end of the oil pattern. Any bowler who sees more skid than they like on heavy patterns can easily adjust their coverstock with an appropriate pad to get their Mighty started earlier on the lane.

When we moved to the medium pattern, the smoother surface finish was a benefit over the rougher cover of the first Guru for both our Stroker and Tweener testers. It allowed the Mighty to glide through the front more easily and save more energy for the back end. When the pattern started breaking down and the testers started moving left, the smoother box finish helped kick the corners out much better than the sanded box finish of the original Guru. Cranker, on the other hand, saw way too much total hook on this pattern. After a few shots, he added a coat of Royal Shine polish to his ball’s cover. This gave his Mighty the extra length it needed to match up better to his high rev game on this pattern.

When we moved to our flatter sport pattern, the box finish was best for all of our testers. The Mighty’s coverstock was plenty strong enough to hook through the oil toward the end of the pattern, while the smooth 4000 grit finish of its cover kept it from hooking too early and hitting flat.

Performance Ratings

The change in coverstock and box finish from the original Guru results in the Mighty Guru being more angular at the breakpoint. This will let bowlers open up the lane a little more than they could with the original.
Even with the 4000 grit finish, the Mighty Guru still picks up very strong in the midlane. This keeps it from sliding too far down the lane, allowing it to provide a big overall hook, just like the original Guru.
Back End17.5
The Mighty's hybrid coverstock helps it to retain more energy for the back of the lane than the original solid-covered Guru. Bowlers who like the big overall hook of the original but who want a little more recovery at the back of the lane will find that in the Mighty Guru.
Total Hook56
This ball offers the same amount of total motion as the first Guru, but with a little different shape getting there. This one is a little cleaner in the oil and a little more angular at the back end, with the end result being the same amount of total hook.


The added length and back end motion from the original are the big positives of the Mighty Guru. This ball will allow bowlers to open up their angles more than they could with the original.


Like the first Guru, this one is more suitable for use on conditions that have a good amount of oil. There are plenty of better Radical options for medium and drier patterns.

Overall Summary

The Mighty Guru offers the same large amount of total hook as the original Guru. Its hybrid cover will clear the front of the lane more easily and allow for a bigger change of direction at the breakpoint and back end.

Additional Radical Guru Mighty Resources

Click here to visit Radical'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.