There is no way that you should not be stretching before bowling and for that matter ANY spaort. The last thing you want to do s pull a hamstring at the foul line. Stretch before EVERY game regardless of the opinions of others. For me it feels werid not to stretch before playing; ergo, I stretch out before EVERY game. You will find out sooner or later, being the easy way or the hard way, that you must do this, especially if you are getting older.