Let me start of by saying I know nothing about drilling balls! Your question made me go back and look at the DRILLING INSTRUCTIONS received with NEW BALLS. I have accumulated quite a few.
DYNO-THANE makes a comment on their sheets .. The Following layouts are for right-handed players. Remember to flip or rotate to produce "mirror-image' for left-handed players. I also see where Hammer states ..All diagrams are for right handers. Reverse diagrams (mirror image) for left handers. Storm states The following layouts are for right-handed players. Remember to flip or rotate to produce 'mirror-image" for left-handed players.
I don't see similar notes from either AMF, Lane1 or Roto-Grip but it's my guess that you have to do mirror images for left-handers!
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Hit them light and watch them fight
J O E - F A L C O