Just back from trip and have a practice in driving range. Sorry for the late reply.

lgskywalker37, the left hand cock of RHD can add power to my swing but not easy to manipulate and will practice more.

msklar92, when not feeling the right swing, the ball flight is very high but distance loss very little, may be within 10%.

shootin4par, your advise will absolutely remind me to make a good swing. It’s a pity I have no camcorder.

After practice with all your advice, I guess I found the main problem. I can’t hit down the ball consistently so ball launch at a higher angle, high ball flight and quick finish with bend left and right arm. If I can hit down, I feel solid, well compressed, ball flight from low to high, longer distance, clear feeling of flat left impact and flat right after, both hand straight, nice followthrough and finish action. But I really don’t know why sometimes I can hit down but sometimes not. I’ve deliberately tried to hit the ball first and then the ground but my swing hinder me to do that which make me crazy