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Author Topic: What is your Standard Deviation?  (Read 3839 times)

CountryClubBowler

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What is your Standard Deviation?
« on: January 25, 2004, 10:47:40 PM »
With all this talk about highs and lows, I got to thinking, how do you determine HOW consistent you are?  I know this topic came up a while ago when someone asked if you were a guy ON your average or around it.  I.e. 150, 200, 250 for a 200 avg bowler, or 190, 200, 210 for the same average.  

Well my standard deviation for a league where I book 171 is 28.78.  That is a lot in case you were wondering.  It roughly means I am an average of 28.78 pins away from my average during a game.  Meaning I either go low or high.  Generally I think it is because I go higher than my average by a lot, but not often.  I go below my average often, but not by a lot.  (I only rolled 6 games out of 54 in the 170s.)

Here is how you figure it out in a real easy way.  Unfortunately you need the data/scores of all your games in a league to properly calculate your Standard deviation.  You just throw them into excel, and in another cell type

=stdevp(
and then highlight all the cells you want to include, (those with scores), close the parentheses,  and press enter.  It will calc your standard deviation.  

This provides a good indicator of how consistent you are on a game to game basis.  Generally the larger the SD is the more inconsistent you are, with some exceptions to the rule.  Notably, when you have very high games that will throw the SD off by a bit.  But the more games you have the more accurate the SD will be.  You can do the same thing with series.  My stdev for series is 54, so my average distance from my average series (513) is 54 pins.  And that is also generally true based on a cursory glance at the data.  

Of course this is only as useful as any other statistic is in any other situation (indicative of the general, but not specific).  But it also provides a much needed break from work for me.  

CCB
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I bowl at country club bowl...not a very inventive name now is it.

 

serice

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Re: What is your Standard Deviation?
« Reply #1 on: January 26, 2004, 02:03:52 PM »
Okay, until I have the time to enter all my scores I like this statistic that my bowling program gives me:Over average percentage of time by game.  
Example:
Game one - over average 72% with a 172.11
Game two - only 61% with a 170.72
Game three - only 67% with a 172.72

Current average for the league: 171.52

Ishmael

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Re: What is your Standard Deviation?
« Reply #2 on: January 26, 2004, 02:19:09 PM »
Here's probably more information than you could ever want to know:

Game.....High....Low.....Average.....Standard Deviation
1............235.....157......200.3...........22.5
2............289.....147......198.7...........33.0
3............263.....144......193.9...........35.8
Total......289.....144......197.6...........30.6
Series....514.....721......592.9...........57.9

Scolai

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Re: What is your Standard Deviation?
« Reply #3 on: January 26, 2004, 02:58:38 PM »
Here it is, for those of you who care:

Game 1 Standard Deviation: 28.57
Game 2 Standard Deviation: 34.44
Game 3 Standard Deviation: 26.16
Standard Deviation Totals: 30.85
Series Standard Deviation: 58.58

I have no idea what all of this means.
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Scolai

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10pin2002

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Re: What is your Standard Deviation?
« Reply #4 on: January 26, 2004, 04:02:08 PM »
Now, after you know all this information, you can do a standard t-test to determine whether there is any statistical difference between your 1st, 2nd, and 3rd games.

I've always wanted to get around to this but I never have.  The end of this year when we get the game-by-game printouts, I'll have to do the stddev and t-score tests and let you know how they end up.

CountryClubBowler

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Re: What is your Standard Deviation?
« Reply #5 on: January 26, 2004, 04:18:14 PM »
hey 10pin,
what is a T test again?  It's been a while since I took a stats class. I barely remembered how to do SD by hand...
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I bowl at country club bowl...not a very inventive name now is it.