OP,
In order to gain accuracy with an overhand shot, aim and lead and throw with your elbow instead of your shoulder. And for goodness sake, don't throw with 100%.
Make it more like a tennis serve than a baseball throw.
Throw leading with your elbow at about 75% power to improve your accuracy.
Thanks! I'll definitely have to try putting a little less on it and make sure to keep an eye on my elbow when I go out to the course today.