How did the Rule of 31 come about in bowling?

[Hammer]

I saw the link posted by bowl1820 about bowling instruction. In there the instructors talked about something called Rule of 31 to figure out your breakpoint on a given oiling pattern. For example if you are bowling on a 40' house pattern you subtract 31 from that number which would be 9 and that would be your breakpoint at the end of the 40' pattern. That wouldn't be cast in stone but it would give you an area to shoot for like maybe the 8 or 10 board. My question is how did they come up with the number 31? Why is it 31 and not some other number?

[bowl1820]

I saw the link posted by bowl1820 about bowling instruction. In there the instructors talked about something called Rule of 31 to figure out your breakpoint on a given oiling pattern. For example if you are bowling on a 40' house pattern you subtract 31 from that number which would be 9 and that would be your breakpoint at the end of the 40' pattern. That wouldn't be cast in stone but it would give you an area to shoot for like maybe the 8 or 10 board. My question is how did they come up with the number 31? Why is it 31 and not some other number?

First it's the Exit point formula, it doesn't give you the break point. It just shows where the ball should exit the oil at the end of the pattern.

The exit point formula is from a Joe Slowinski article and is based on information in Neil Stremmel's article, Entry Angle, Part 3: USBC Research Shows Where Your Ball Should Be to Achieve the Best Angle.(pp. 6 - 8),appearing in Bowling This Month in April 2006.

This Slowinski article is about where it started, the formula was later simplified to the one you seen (The math is simplified by using Pattern Length-31 = Exit Point.).-
http://bowlingknowledge.info/index.php?option=com_content&task=view&id=20&Itemid=46

More explaining about it in this article in step #1
http://bowlingknowledge.info/images/stories/slowinski_btm_3point_targeting_2007.pdf

[bowl1820]

The Exit Point Formula & Mo Pinels Breakpoint Formula:

It's referring to Joe Slowinski's exit point formula (Pattern length - 31= Exit point)

The exit point is just that, the point where you want the ball to come out of the oil, It's not where you hit the entry angle (breakpoint).

Once it hits that exit point using various launch angles. Then the ball will travel distance X out of the oil and turn (at the break point) to line up with the desired entry angle.

The problem with it is that doesn't work right on shorter patterns. (Mo Pinel said it's not accurate and shove it)

Mo suggested on how to find the board the breakpoint is on. By looking at the composite graph of the oil pattern. (you can also find it by looking at the Lane Machine Settings chart)

What you do is look for the highest corners of the red bars on the bar graph and subtract 3. That's the place to start looking for the breakpoint. (But this doesn't tell you how far down the lane it is)

Remember that the loads are applied to the buffer brush, so ALL the forward loads affect the breakpoint.

Here's a example: using Kegel's DEAD MAN’S CURVE 3043 Pattern
Direct Download the pdf for the pattern here http://www.kegel.net/V3/PatternLibraryFunctions.aspx?OPCODE=DOSYAINDIRT&ID=607&Type=2

or see the webpage here and click on composite view http://www.kegel.net/V3/PatternLibraryPattern.aspx?ID=607

http://s11.postimage.org/90j2ipsdv/comp.jpg
In this example the highest red bar is on board 14, so 14-3= 11. That's where you start looking for your breakpoint.

http://s10.postimage.org/8f1g8i8l5/comp2.jpg
from the Lane Machine Settings chart

Now my thought is not so much to shove the exit point formula, but to look at the situation and see if it would be beneficial if used (on The longer patterns).
Like use the end of pattern minus 31 to give you a starting place, when the only info you have available is the length of the pattern.
And if possible combine it with Mo's suggestion.

And yes these are not cast in stone.

Ultimately the lanes will dictate how they should be played, these are just starting points.

[RobLV1]

The Rule of 31 applies to sport shots only. It cannot be applied to a typical house shot. For example, a 35' THS is normally laid down using a Christmas tree shape. Little oil outside of 5 board up front. Little oil outside of 10 board at 15-20 feet, and little oil outside of 15 board at 35 feet. If you tried to applied the Rule of 31 to this pattern, your ball would need to be at four board at 35 feet. The problem is that to get there, you would be in high friction well before 35 feet and the ball would already be hooking. To play a short house shot, you need to play as far left as you need to (for a right hander) to make use of the tip of the Christmas tree to get the ball down the lane. (Thanks Al)

[JohnnyG]

It talks about utilizing the rule of 31 to find the break point on the lane.