Score of Demarcation

[1VegasBowler]

On the sidebar of being able to score bowling, I began bowling in the dark ages before automatic scoring systems, we were glad to get the overhead projector with transparent plastic sheets allowed the scores to be read without walking up to the scoring table and looking at the paper sheet.
I also bowled with a couple of crazy engineers, who thought that scoring the night using roman numerals would be a fun idea, to keep it symmetrical we also scored the other teams sheet, I lost interest somewhere along the line but I do recall it being a challenge to keep everything in roman numerals.

We had glass at the scoring table and used those white pencils for the overhead projection. But we also kept track of our marks as well.

[Mike White]

Bowling is first and foremost a contest, so taking that as the critical factor in all of this wouldn't the minimum acceptable score be one pin more than your opponent.

In theory that sounds good, except what happens when your opponent shoots a 300 game?

Even if you match him with a 300 of your own, it's not acceptable by your criteria.

[Mike White]

If memory serves correctly from 25 years ago at work we used 3 standard deviations.
No computers just a calculator and a paper chart.
We plotted the readings (game scores) and after 30 games put in a line with the average. Say 200
Then on the bottom we put in the difference from game to game say 180-176-222-211-230-200 etc
Then got a average of the differences 4-46-11-19-30 the avg. would be 22
Then mult. by 3.27 and got so the difference would no more than 72
Then the top was by 2.66 meaning no score would vary more than 53 pins son between 253 and 147.
I haven't done it in years but that might be close.

You know what they say about things you put into your memory...

Wait a moment while I look it up..

Oh yeah... Use it, or lose it.

I looked at your 6 number sample, and calculated the standard deviation using the method I remembered, and I calculated a number very very close to 22.

Actually the standard deviation was 22.0037875528, but we can call it 22 for convienence.

Looking at your result had me confused for a bit.

It appeared you may have been taught a very efficient short cut method.

That was until I remembered that the order of the scores would have no impact on the standard deviation.

I reordered the scores to 176-180-200-211-222-230.

Using your method the value changes from 22, to 10.8.

Clearly the fact that the first try was so close was a coincidence.

Then mult. by 3.27 and got so the difference would no more than 72
Then the top was by 2.66 meaning no score would vary more than 53 pins son between 253 and 147.

Not clear what you're doing with these two lines.

Your numbers have an average of 203.167

3 standard deviations would 66, so the range would be 203.167 plus or minus 66.

We would expect 99.47% of scores to fall within the range 269.167 and 137.167.

I don't see 3 standard deviations as being a large enough range to use the word NEVER with.

[fordman1]

I was in a hurry and just said 200 I didn't add it up just showed how we got the range. It was the difference between one measurement and the next. You averaged that to get your range. Your upper control limit on the range was 3.27 times the average difference.
Your upper and lower on the game scores was plus or minus 2.66 of the average.
Remember we were measuring sheet metal that had been stamped into hoods, doors and fenders etc. There was tolerance of between .25 and 1.5 mm for size and margins depending on the part. Everything went through a checking fixture.

Now I have to do my league sheets. Lots of big scores last night. Had 2 300's and a 845. Can't beat speed and hand.

[Tony]

In theory that sounds good, except what happens when your opponent shoots a 300 game?

Even if you match him with a 300 of your own, it's not acceptable by your criteria.

If your goal is to win, then anything short of that isn't acceptable, you might win some games with a 172 and lose with a very high score. Depending on handicap you can beat a 300 game, if you get pins and the 300 bowler doesn't you don't have to beat him scratch to win the game.
One of the guys I bowl with shot a 324 with handicap game yesterday, so he beat his opponent who had less handicap no matter how well he bowled.

It's not a perfect system no matter how you figure it, either using the very real goal of winning or using statistics to figure out what you should theoretically be satisfied with. It seems neither solution is the answer.

You can't use statistics to determine the separation of feeling you shot an acceptable game or an unacceptable game, there are more factors than simply your average that influence where that point lies for some people and for others it's a flat line, If I shoot over xxx I'm happy with it....but are you still happy with your xxx number if you ended up there by opening in the 10th , probably not as much. Also lane conditions, guys scoring around you and your mental and physical condition also have an effect, at least for me.

[Mike White]

I was in a hurry and just said 200 I didn't add it up just showed how we got the range. It was the difference between one measurement and the next. You averaged that to get your range. Your upper control limit on the range was 3.27 times the average difference.
Your upper and lower on the game scores was plus or minus 2.66 of the average.

Ok, you had a process that was easy to calculate, and produced acceptable values for your application, just realize that those aren't "standard statistical rules".

Remember we were measuring sheet metal that had been stamped into hoods, doors and fenders etc. There was tolerance of between .25 and 1.5 mm for size and margins depending on the part. Everything went through a checking fixture.

Now this is totally unfair. I have a hard time remembering things I'm supposed to, and here you're expecting me to have remembered something I've never known.

[Jessiewoodard57]

You know we all have bad days but imagine bowling a 100 on national TV ....poor Tom had a bad day. Then I think of Belmo at the summer swing. Wow who would have thought such bad scores? When I have a bad day (often lol) I just chalk it up as just another day...this too shall pass.

[1VegasBowler]

You know we all have bad days but imagine bowling a 100 on national TV ....poor Tom had a bad day. Then I think of Belmo at the summer swing. Wow who would have thought such bad scores? When I have a bad day (often lol) I just chalk it up as just another day...this too shall pass.

His revenge ended up winning that same tournament later on.

[SAbowler]

Ok, what score should you NEVER go under regardless of the circumstances, you know the Score of Demarcation

I've had some turds this year, 133, 143. But to me I'm disappointed at sub 175. Sure 175 isn't that great but a few splits here and there and you're barely treading water.

If I bowl below average, I'm disappointed, but if I throw WAY under average, say 20pins or more, I'm pi$$ed. Seems I'm pi$$ed quite often! LOL

[Chamiso]

I currently average around 145 I consider a bad day around 120. Though unfortunately I end up having a really bad night like the other week where I ended up with a 94, was really upset at myself there since it was below 100. I hadn't did that bad in over 6 months until that night...