Even with bowling centers that have easier house patterns which takes less effort to roll a strike, this tip affects all types of bowler's scores. Beginner to advanced, cranker, tweener or stroker, I can sum this up in one word, SPARES! Spare shooting is still the most important part of the game of bowling.
It can cost a professional a match in tournaments or be the one thing that keeps you from that new target score. Doing a simple calculation, one missed spare is minus 11 pins. This is usually pretty close. As an example, if I were to have a clean 200 game, but with an open frame or a missed a spare, I would have about a 189. This does depend on your pin count (Note: This is just a ball park figure).
Another way to look at it is I had a 200 game with 1 open frame, but I would have had about a 211 if I would have filled the open frame with a spare. To sum it up I know it sounds basic, but it is true, spare shooting is still the most important part in bowling.