Right now I am in the middle of a statistics class and we recently went over standard deviation. For those of you who don’t know what standard deviation us I will bring in Wikipedia.
Standard deviation is a widely used measure of variability or diversity used in statistics and probability theory. It shows how much variation or “dispersion” exists from the average (mean, or expected value). A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data points are spread out over a large range of values.
What I am doing is pretty much, “who’s batting average fluctuated the most over the entire season?”
For Brian McCann I will show you how the math is done for the stat junkies out there who care:
the rest after the break…
We need to the average for each month. McCann’s were .301, .304, .342, .275, .146, and .200. Then we have to use the formula* (x1- season average)2 + (x2- season average)2 … and so on until we have used each individual average. X represents the monthly average. After we add them up we will take the square root of the number to find the standard deviation, and find out who really was the most ‘consistent’.
*you can also do all of this with a graphing calculator…
McCann’s standard deviation came out to be .0736. The higher the number the less consistent the batter. Now we will repeat for the rest of the team.
Bourn (including time with Astros)- .0338
Apparently in 2011 Michael Bourn was the Braves most consistent hitter. Don’t read into this too much however because I only used the averages each month instead weekly which would work much better. Also, missing time (McCann, Prado) can really skew the data. It’s not an exact measurement when you use it the way I did, but it seems to be at least reasonable. I mean, Michael Bourn was the leagues least volatile hitter at one point last season.
Take it with a grain of salt. This was more of just a curiosity piece but I am not surprised at all that Michael Bourn, Chipper Jones, and Freddie Freeman were the most consistent hitters on the team. Are you?