This is from Bowling ball.com, I thought I would reprint it here.
It's a game of adjustments,
But it's also knowing what adjustments to make.
In a game you do not have frames to experiment with.
So do your "research" during practice games, and
don't look at scoring at practice games.
Also keep a log, You will never remember what
worked and what didn't with out one.
Only adjust if you feel you made a good shot.
Target, speed, release and the like.
Do not make any moves until your shots are
consistent, otherwise you have know idea were your at.
When I say a good shot, I refer to the basics of ball delivery,
If you delivered the ball without error in your delivery, BUT,
still missed the pin, now you adjust you stance or target.
Just like shooting a rifle, it takes a number of basics to make
a "good" shot, but don't adjust your sights until you can hold a
tight group or pattern.
I like to say, I know what I want to do on each shot,
however the body and mind don't always cooperate.
Or a million things can go wrong, before I get to the fowl line.