Well I am lefty so this is reversed, but I went through the same thing as well.  Until an older bowler told me what I was doing wrong, so this may be your problem as well.

First if you're leaving 10 pins consistently and hitting pocket, move 1/2 board to your right with your feet keeping the same target and see if that doesn't carry the 10 out.....if that doesn't work....move another 1/2 a board...still doesn't work?  Then the problem might be in your release.  If you grab the ball at the end....chances are you won't carry.  The release has to be nice and clean where you get all the lift with your fingers and no thumb.  I know that if you have an inbetween hit and u grab it, you won't carry 98% of the time...but if you're clean...you have a much better chance.  So try those things and see if they work for you....if not that I have no idea.

Good Luck!
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My Arsenal:
Brunswick Ultimate Inferno, Hammer Road Hawg, Columbia 300 Action Packed, Rotogrip Spare Tire

I disagree with the new ball choice. There are many things you can do. Some grab harder, some try softer at the release and let the ball roll earlier. Some try to circle the release a little. Some switch balls. In the end, you need to adjust your angle. Sometimes a board here or a board there isnt enough. Sometimes you need to try a different zone of the lane to carry.

Another thought on this topic is that if you are bowling on a THS---the lane is available, try something drastic. The shots allow for it all the time so it shouldnt be too tough.
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Only Losers Feel Pressure
www.thetimekillers.com

you should simply get a lane pattern ball if u can afford it...I can grab em, loft em, drop em throw em 20lbs and they still carry... Of cousre though brunswick makes em so just get an inferno if not....then u have no problems!