My problem is what do you do when your "line" passes directly over a loose board or a board with a big chip taken out of it? Now what do you do?

What happens if the nozzel of the machine that passes over that board at the point is clogged? Or the batteries in the cordless machine are getting low or to the point where the machine is stopped on the lane and has to be drug back manually?

These kinds of things happen every single day in bowling centers. If you are using these lines and numbers as a means to line up, I don't see how you can depend on them lane to lane, day to day.

I know a lot of work went into creating these numbers and lines, but to me they just seem totally impractical.

Erin

This is my kind of thread I am sad to say.
I am in order of competence an engineer, software programmer and bowler. After reading through this thread I would like to suggest that the path of a bowling ball can either be described as a straight line or a logarithmic curve but not a simple arc.
Wikipedia Logarithm

Calculating this curve based on simply fitting the data to match the observed values would be fairly trivial. However the variables that would make this data more predictable are quite complex. For example increasing speed would flatten the curve increasing revolutions would accentuate the curve. The more challenging problem would be to allow for the effects of the cover stock and the oil pattern and the resulting coefficients of friction at various points along the balls path.
The above does not even address the issue with variations in release ball to ball etc.

I will however mull the problem for a few days to see if I can contribute more to the thread

All the best

BowlCalc

Finally, a constructive discussion has emerged.

I'll use myself as the beta test, here, and hopefully respond to your concerns.

First, let's clarify some questions.



Nowhere does Joe state that your ball will follow that 6* angle line. He simply states to note where the ball crosses that line. That is the indication of which ball chart calculations to use. If it crosses at the 7.5 board, then use his calcs for 7.5 to move accordingly to achieve a pocket hit. If it crosses at the 2.5 board, use that chart.



This is your misconception. The points on that line where your ball hits is not a target. It is an observation of your ball roll. His starting premise is that the combination of your ball crossing the 6* line in relation to a pocket hit defines your ball path line. A ball crossing the line at 15 boards into the pocket would have a fairly straight trajectory. A ball crossing at the 2.5 board would have an significant back end reaction, maybe a skid/Flip. But, it's the combination of pocket hit and crossing point.



Again, don't be obsessed with the 6*angle line. It's not a target, and most likely your ball will not roll on it. The line is simply a series of co-ordinates via a calculation that is fairly accurate. And one co-ordinate of that line crosses the 7.5 board at 52.27 feet from the foul line. His movement calculations, left or right are the important points.

I don't have time to go through all of your comments. I want to get to your lane drawings. Specifically, the one where you drew in the red line straight shot and the yellow probable ball path. First, on the yellow ball path. I probably wouldn't change much, since that line hit the pocket. And, your drawing shows a fairly shallow ball arc that hits the 6* line at maybe 14 bd, and a 3* entry angle. I'd maybe move a bd right with that shot. Don't know what Joe''s 14 bd chart would show, but I'd bet it would be close.
But, on the red straight line, look at where it hit the 6* angle line. Assume it's the 7.5 board, then look at Joe's 7.5 calcs. He has a reference of 10 bd at the arrows and 10.99 bd at the laydown. That's pretty straight and coincides with your red line. Then he calculates where to move. It could be the 4 bd at the arrows, but the ball start has to be at the 2.69 board. That gets you to a point 60 feet down lane to the pocket. If my calcs are correct, it would hit the pocket at the 16.96 bd. Or you could target the 17 bd at the arrows with a laydown at 21.03, which would get you to the pocket. I have trouble with this calc, since I see it will hit at the 16.36 board, and probably prone for deflection.

Do either of these enter at 6*? Absolutely not!!. But, do they get you to the pocket? Yes.

Joe changed the ball line based on the crossing point that you noticed when the first ball crossed his optimum 6* angle line. His chart shows either an outside straight line to the pocket or a straight line down the center. And, some points in between.

Let's get back to his original question. Joe had asked for help in verifying that his calculations were correct. I am not capable of doing that. But, maybe you are. Or others?? He asked for confirmation of the statistics, not a critique of his premise.

If his calculations are off, then he needs to go back to the drawing board.

Let's step back even further. His chart is straight lines, from the foul line to a point on the 6* line. If the ball follows that path and crosses the 6* line at that point, the ball will not hit the pocket.



Actually it's your misconception. Again, his chart draws a straight line from the board the ball is set down on to that point on the 6* line. He gives you 3 points, all in a perfectly straight line. There's no accounting for ball roll at all. If your ball actually reaches that point, it means it went perfectly straight, even through part of the dry back end. If it does this, you're not going to hit the pocket. You're more than likely not going to even his the 3 pin.




It is the target. How can you say it's not? He chart in bold letters says Target 7.5 Board@ 52.27 Feet. Why would you call something a target if it wasn't a target? And again, it's a target on a straight line. And one of Joe's assertations is that this will give you a 6* entry angle. He also said that he thought that all balls started at the same trajectory that hit the pocket would all have a 6* entry angle, regardless of the ball path. He's very much claiming that this gives you a 6* entry angle.



It never hits the 6* line. The only point they share is right at the pocket. If it crossed over the line, it would be light in the pocket. If it only meets at the one point at the pocket, it's a shallower angle. If it follows the line, it would be a 6* angle.



The red line, as I said in the post, is straight up the 10 board. I wanted to illustrate how much farther the ball would have to go to get to the 6* line. So since it's straight up the 10 board, it intersects the 6* line at the 10 board.



That's not what he's doing. He's just drawing straight lines from the foul line to a point on the 6* line. Reread how he said he used this on the Scorpion. This chart doesn't calculate anything for you. It's simply a bunch of straight lines from the foul line to targets on the 6* line. He never made any claim that you can look at the point where you cross the 6* line and adjust backwards.



He did what he'd normally do, in his head, but instead of just telling himself that he was going to stand at a certain spot and aim at a certain spot, he picked lines from his chart instead. Again, the chart didn't tell him what to pick. He made that decision. The chart is just a bunch of lines.



His calculations are correct. They, again, draw straight lines from the foul line to a target on the 6* line. Nothing more, nothing less.

Unless you end up creating > 6* entry angle, your ball will never cross that line on a shot that hits the pocket. If you end up at 6*, and your ball rolls out before it hits the pocket, it may roll on the line for a short period.

I just really want to clarify here that the system is a set of adjustments - there may be some patterns that they work on - I seriously doubt they will work on all. On a sport shot, I often find I need to make a 1 and 1 move - this system doesn't give me that, and I probably won't use it.



My constructive feedback on the validity of the calculations is that the first arrow is at 12 feet, and the 4th is at 15 feet. 2nd and 3rd at 13 and 14, respectively. If you're playing pretty straight it's not too important, but if you're crossing a lot of boards, hitting the 20th board at 12 feet could mean hitting the 19th board at 15 feet. Something to keep in mind when using the chart to find your target at the arrows.

I didn't actually run the numbers.

The chart attached below includes Target Lines to the exit points for the sport patterns (Cheetah, Viper, Chameleon, Scorpion, Shark).

The exit points are based on the pattern length minus 31 theory proposed by Joe Slowinski. I am not saying whether the theory is correct, but at least one poster on this thread suggested such a chart would be more valuable than one with points on the 6-degree line. Hopefully, my math is correct.

Good luck and good bowling.

Joe - Do you take into account that the arrows aren't all at 15 feet? I think Cgeorg mentioned above that the 1st arrows are at 12, the second are at 13, 3rd at 14 and the 5th at 15. I can see where something like this would help people get lined up to get the ball to those points down the lane.

Question lefty? Why is it that using the pattern length minus 31 formula and figures makes it somehow more valid than using what was posted earlier?

I am not arguing whether the ball achieves a 6 degree entry angle, because to be honest I don't care if it ever does. I think the best part of the chart is that if notes were added by the bowler, it could help one adjust over time. Every person has a formula running in their head that gives them what adjustment to make based on what is going on down lane, why is it that Joe shares his formula that he runs in his head and its wrong? If it works for him, it works just fine, no different than someone else using a ball that doesn't work for me and they score great. Each individual is always decoding the lanes, if Joe is trying to go out of his way to help out a new bowler that is completely lost in the game, why is that such a bad thing. Sure you think its wrong, you made your point, move on.

The short answer is yes. For this and the original chart, below are the coordinates I used for the arrows, foul line dots, and approach dots. In each case, the center of the marker was used to determine the coordinate. For in-between boards, the center position was calculated along a line that joins the center of the existing markers.

(x=inches, y=feet)

Arrows:
1st (4.78846, 14.15625)
2nd (10.10897, 14.65625)
3rd (15.42949, 15.15625)
4th (20.75, 15.65625)
5th (26.07051, 15.15625)
6th (31.39102, 14.65625)
7th (36.71154, 14.15625)

Foul Line Dots:
1st (4.78846, -0.29167)
2nd (10.10897, -0.29167)
3rd (15.42949, -0.29167)
4th (20.75, -0.29167)
5th (26.07051, -0.29167)
6th (31.39102, -0.29167)
7th (36.71154, -0.29167)

Approach Dots:
1st (4.78846, -11.875)
2nd (10.10897, -11.875)
3rd (15.42949, -11.875)
4th (20.75, -11.875)
5th (26.07051, -11.875)
6th (31.39102, -11.875)
7th (36.71154, -11.875)

I expect there may be some differences from one bowling center to another, as the USBC specification do not requires specific placement, just placement within a range.

Joe, thanks for the sport pattern chart. Incidentally, my downlane target for my house shot is about the same as the Viper pattern (40 foot house shot, but with the taper it's not 40 feet nearer the edge), so that chart should be usable this Wednesday night. I'll try it out and let you know. There have been a few nights when I haven't had to move, and a couple where I had to change my breakpoint, but for the most part I am able to make standard adjustments. Like I said, I'll let you know.