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ATTRIBUTE INDEX

Bowling Balls by RG

Radius of Gyration measures how the mass inside a bowling ball is distributed relative to its center. Low RG balls rev up earlier on the lane. High RG balls save energy through the front and rev up later. The USBC regulates RG to a range of 2.46 to 2.80 for 15-pound balls.

By the BowlersMart Pro Shop Team. Last reviewed for the 2026 season.
AT A GLANCE
21
RG values indexed
3
Tiers: Low / Med / High
15 lb
Reference weight
USBC
Approved specs
HOW TO READ RG

The 3 RG Tiers

Each RG value falls into one of three tiers. Knowing which tier you need narrows the search before you drill down to specific values.

LOW RG
2.46 to 2.50

Earliest roll. Strong mid-lane read. Best for heavy oil and slower bowlers.

MEDIUM RG
2.51 to 2.56

Balanced roll. Versatile across most lane conditions and rev rates.

HIGH RG
2.57 and up

Latest roll. Maximum length. Best for dry conditions and high rev players.

THE INDEX

All RG Values (Low to High)

Click any RG value to see every BowlersMart ball with that exact specification.

Jump to Low ↓Jump to Medium ↓Jump to High ↓
LOW RG (2.46 to 2.50)

Earliest roll. Strong mid-lane read. Best for heavy oil and slower bowlers.

MEDIUM RG (2.51 to 2.56)

Balanced roll. Versatile across most lane conditions and rev rates.

HIGH RG (2.57 and up)

Latest roll. Maximum length. Best for dry conditions and high rev players.

Other Core Attribute Indexes

ATTRIBUTE

By RG (Radius of Gyration)

Browse balls indexed by how early or late their core revs up.

Open RG index →

ATTRIBUTE

By Mass Bias Strength

Browse asymmetric balls indexed by how strong their backend break is.

Open MB index →

ATTRIBUTE

By Core Differential

Browse balls indexed by total flare and overall ball motion strength.

Open Differential index →

NEXT STEP

Know the RG you want? Get fitted at a pro shop.

Picking the right RG is one variable. Pairing it with the right layout for your PAP and rev rate is the next. Visit a BowlersMart pro shop for a certified fitting.