1. I know trial and error is the best way to learn, but when the oil transitions, other than moving your target or your feet, is wrist position upon release something to try first before doing a ball change?
Josh - This is a great question Tim. Bowling can be so complex because there are so many variables you can change when transition hits, but the bowler who figures out the right one first is usually your winner. I would suggest figuring out which variable you are the best at and go with that when the time hits. Whether it be moving your feet, your eyes, your hand position or even your speed. There isn't one correct answer for everyone, it is different but understanding what works for you is best.
Craig - Wrist position is an option to combat lane transition, but it's not that simple. What the right answer is, and what order to do them in depends on your goals. Are you trying to combat lane transition on sport patterns or house patterns? In a league setting, or a tournament setting? For the league bowler, who bowls on house shots, keeping it simple is best. You shouldn't need to change wrist positions or have a 6 ball arsenal to deal with lane transition on a house shot. 3-4 balls and one type of delivery should do the trick for most house shot transition as long as your 3-4 balls are a good variety of performance types and you understand your equipment well. Once you get into the sport shot world, everything becomes a bit more complicated. I'd say if you are trying to average below 180 on these patterns, then the same rules apply that I mentioned about house shots.If you are trying to get to 190-205 on sport shots, then a 6 ball arsenal will be needed and you will either need a couple wrist position changes or a couple speed adjustments. To become a 215+ average player on all variations of sport patterns you will need the whole gamut of options and understand how to use them and when to use them.
2. When is a good time to start replacing balls?
Josh - This brings of a great topic in today's environment where balls wear out faster than they ever have. Remember this, duller bowling balls will tend to die out faster than polished bowling balls because they are made to absorb oil faster and this clogs the pours of their coverstock. In either case, it is important to maintain the coverstocks on your bowling balls as frequent as you can to increase the longevity of each ball. A good time to replace bowling balls is when you have lost the desired reaction of that ball after trying to change the surface many times. This means the overstock has been worn down and there isn't the power left in the ball that it used to have when you purchased it. Bowling balls are like cars and wear down over time after you have put many miles on them.
Craig - I guess like my other answer, it depends on your goal. Do you need your bowling ball to perform a tiny bit better then what it is now, or do you need something completely different then your current ball? If you need a small performance boost out of your current ball, I'd suggest oil extraction methods like the Wave or Detox. In many cases, if you get a good oil extraction and some resurfacing done your ball should perform quite a bit better and get you that small performance boost. If you are wanting something that is an entirely different motion, or something that hooks a lot more than I would go straight to a new ball as soon as you start feeling that way about your current one. Just a few months ago a Craig Sheen bowled back to back 300 games with an original black hammer and on the other hand we see people bowl 300 games all the time with balls that they just recently drilled. My point is that the bowling ball isn't really going to tell you if you need a new ball or not. Your lane play preference and how you prefer your ball to perform will tell you if you need a new ball.