While I picked up bowling in the mid 70's, I do have some insight into the differences between the "then" and the "now", because the center here had tracked out wooden lanes and low tech balls, but in the ensuing years has gone to full synthetics.
In the "old" days, the shot here was put out manually with an old "line-a-duster" and oil soaked rags cut to reach from 10-to-10 and dragged down 33 feet. Stripping the lanes was also a manual operation, using that same old "line-a-duster" and a soapy degreasing agent followed by a clean towel.
There was an obvious track area worn into the wooden lanes, going directly across the second arrow. The pocket wasn't hard to hit, but that track area was mre forgiving. Put the ball into the track area, and a higher percentage of lesser quality shots ended up hitting the 1-3. For what it's worth, it seemd to mildly guide weak shots to the pocket, but also seemed to hold stronger shots there as well. With balls too weak to overcome the track, putting a ball into it pretty much meant at least hitting the pocket.
Carrying? Now that's a whole different issue. Even with the best balls available AND using the track, you still couldn't generate nearly the angle you can today, especially if you got your feet very deep. Even with the drier area outside, the balls just wouldn't turn like they will now, and everybody knows entry angle increases carry percentage, right?
O.K., fast forward to now and do a comparison:
1. 1970's rubber and plastic balls VS todays reactive missiles with gyroscopic weightblocks. Many times the friction and ability to "self-correct" without nearly the deflection through the pin deck.
2. 1950's tracked up, low friction wooden lanes VS todays modern, high-friction synthetic surfaces that wear very slowly, giving the bowlers playing deeper the friction needed to "turn-the-corner" without needing a track to help.
3. Phenolic pin decks and high C.O.R. kick backs with raised flat gutters which may even be spring loaded.
4. High grade, lower weighted pins, full of voids that lower their center of gravity and coated with high impact synthetic coatings which maximize whatever impact has been imparted to them.
So, what's changed? EVERYTHING. From the way the sport was played to the mindset of the players. From the fact that bowling was a very SIMPLE sport that was HARD to excel at, to a very COMPLICATED game that many more than ever before can reach the benchmark of a 200 average.
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ILLEGITIMI, NON-CARBORUNDUM!