Two handed spare shooting??

[kbatpba]

Have a question. I have a two handed high school bowler that uses a "house ball" for spare shooting. Have been told that he can use a house ball (with a thumb hole). Is that correct. Thanks

[itsallaboutme]

The following limitations shall govern the drilling of holes in the ball:
Last updated on 04/23
BOWL.com | 15
1.
Holes or indentations for gripping purposes shall not exceed five and shall be limited to one for each finger and one for the thumb, all for the same hand with no drilled holes exceeding 1-9/16” diameter and 4-1/2” deep. (Note: This includes holes required to install removeable devices). The player is required to use all the gripping holes on every delivery with the same hand except when using a house ball.
A house ball is defined as:
i. Being supplied by the center in which the certified competition is being held.
ii. Having a polyester or basic urethane coverstock.
iii. Having a differential RG less than 0.025 inches.
iv. The ball is not drilled to fit the bowler specifically.
NOTE: A ball left in a bowling center by a bowler for public use is not considered a house ball.