I am throwing softer than normal. I have tried to throw hard like i see some people do but i cannot control my release when i do that. I would say i am thowing around 10 to 12 MPH at the 10 pin and throw about 16 MPH strike ball.
Ahem. "You don't have to throw it hard. You have to throw it straight."--CoachJim
I used to struggle as well, but in following CoachJim's lessons, I've made it much less of a problem. I also used to haul around a plastic to take care of these corners, but the way I was flattening my hand (index tucked in close to middle finger, pinkie way out) also works for any ball--whatever's my strike ball at the time, that's the ball that gets thrown straight at buckets/washouts/2-8 sleepers or faded at 3-6-10s and left corners.*
One fairly easy thing (if Jim's covered this same thing, then I apologize) to try is to open your forearm to the target. This follows along with all the other alignment instruction. If you focus on that, then the back of your hand faces your target. Small thing, but it does work for me. I know when I've missed, and those opportunities are far fewer these days, I can look at my hand first to see if its placement is wrong. If not, then it's alignment.
*This is also easier to do by moving my feet way back on the approach from my normal start. I have a freer swing now (thanks CoachJim) so I'm constantly moving up and down now on the approach adjusting speed through ball height--feet above the dots, ball by my hip and conversely with my feet just in front of back dots, ball's up almost above my shoulder, and this is the position I always move for shooting at either corner. Angle BOTH feet properly with shoulders square to the target. Most speed/most straight = most corner conversion with any ball. It's easier done than said. Trust me.