I agree that when you practice alonoe, you don't get the same type of transitions that you might get in a league. But when was the last time that your practice conditions started out the same as a league condition? For me, that is hardly the case. Usually when I go to practice it might be after open bowling, after a league or who knows what. Going to practice "scoring high" is not always the goal. Most of my practice sessions deal more with foot work, hand variations, balance, timing, and lane play. I can pretty much do all this with a plastic ball, some tape, and a video camera. I rarely worry about what happens when the ball gets to the pin area, I worry more about getting the ball from point A to point B, or what is happening on the approach.
If you are interested in practicing for what will happen in a league environment, then you will have to duplicate that environment as well as possible. This would include getting your entire team to join you in your practice session and possibly invite another team to join you to play as the opposing team. Most people don't want to practice that long or it is just impossible to get that many people together. If you can get that done, then I am sure the comraderie is great.
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I am not a pro-bowler, but I do play one on BallReviews.com