Friday Potluck (color calculators, orbits, baseball)

Today is going to be a hodgepodge of what's been happening over the last week. (when I am not at work, working out, sleeping, etc)

Congratulations to my cousin Gina, she gave birth to a beautiful girl, Beth on June 28! :)

The Calculator Rainbow is Back

During the last two weeks, I saw that Staples, Office Depot, and Target is getting ready for Back to School. it must be around the corner, man, we are already in July 2012! Texas Instruments has once again leashed its colorful band of TI-30x iis calcualtors in many colors: light blue, green, orange, and pink. There is also a pink version of the multi-line TI-30 XS in addition to its normal pale blue sibling. Yeah, it is hard to admit to that as a guy, I own anything pink (I called it light red at first). Even Casio gets in the act, at least at Staples, the fx-300ES PLUS has black, pink, and I think green.

I could not resist.

Orbits and Kepler's Laws

A good source to learn, brush up, and/or be entertained is the videos of bestdamntutoring. Saul Hernandez, of bestdamntutoring.com, is awesome in how he explains concepts, he speaks clearly and gets to the point.

Link to bestdamntutoring's YouTube page.

Now you know where I brushed up on Kepler's Laws, in part to hopefully prepare myself for the astronomy meeting tomorrow night (where I am meeting with my good friend Mike Grigsby):

1. Planets travel in an elliptical orbit with the sun at on of the two foci of the ellipse.

Note: The foci are located a*e units away from the center of the ellipse along the semi-major axis line. The variable a represents the length of the semi-major axis and e represents the eccentricity of the ellipse.

2. Planets sweep out at equal areas at equal times. This explains why planets move faster when they are closer to its sun and move slower when planted are away from the sun.

3. The period of an orbit can be described by the following equation:

T^2 = (4 π^2 a^3) / (G M) where

T = period of the orbit
a = length of the semi-major axis. Often, a circular orbit is used instead and hence the radius is substituted for a.
M = Mass of the central object. An assumption is made that the mass of the central object is much larger than the mass of the object being orbited.
G = Gravitational Constant. In space,
G = 6.67428 x 10^-11 m^3/(kg s) =
1.069117097 x 10^-9 ft^3/(lb s).

(Thank you TI-36X Pro. )

Baseball and WAR

In attempt to get a further understanding of Sabermetrics, the analysis of baseball and softball. We all know that part of the game of baseball includes stats galore, and at least in the United States, shaving cream pies and Gatorade baths to game day heroes. I wish there was a golly stat for pies, that would be awesome... OK I am getting off topic.

I took a look the ever vaunted stat, the WAR, or Wins Above Replacement. Basically, if a player's WAR is high, at least a 4, he is doing well. WAR is defined as a measurement of a player's "value" over a scrub (low-level minor-league) player. The goal of WAR is to assign one major value to every player that takes into account everything possible.

Thankfully, sites like www.fangraphs.com has a WAR score for just about everyone who has played baseball (at least in the US).

There are two types of WAR, one for the batters and one for the pitchers.

Generally, the batter's WAR consists of a weight batting average weighed against a dynamic league average, UBR (baser inning measure which is not a rigid formula but made of a lot of judgement calls, whose I don't know), and UZR (fielding rating calculated of the type of play and difficulty factor). None of the formula is straight forward, and as I if understand it, the weights change over time.

I didn't get much into how a pitcher's WAR is calculated, but I imagine it is complex as a batter's WAR.

First of all, where do these analysts get the time to manage the massive amount of calculations? Do they ever enjoy the game? Second, how are the weights determined? So far I have not seen anything on how the weights are calculated - are they determined by complex formulas or arbitrarily?

A Word of Thanks

Thank you to everyone who reads my comments and leave comments. I am very pleased to read that many people are enjoying this blog. This blog is one of favorite things to do. I appreciate the compliments and comments.

Enjoy the day,
Eddie


This blog is property of Edward Shore. © 2012

Taking Some Mystery Out Of Baseball Statistics

Welcome to Blog Entry #70.

A shout to all who are following my blog. Many sincere thanks!

This will probably be my first anniversary post, even though it is still about a week away. I started this blog on April 16, 2011.

If you have any math or calculator questions, please feel free to leave a comment - I will do my best to answer it. Maybe your question becomes a future blog entry. Thanks!




Today's blog entry will cover baseball statistics. Any one who follows baseball, especially in America, will hear tons of statistics for each player, for every single kind of situation possible. I guess this is how a lot of people keep busy watching the sport.

I am going to go over some of the more common statistics. Apparently the only thing complex about statistics is the amount of statistics and abbreviations and not the mathematics itself.

Baseball Stats

BA: Batting Average

BA = H / AB

The higher, the better.

H = the number of hits a player makes. This is each time a player successfully reaches at least one base after hitting a pitch.

AB = number of at-bats, the number of the times a player appears in front of a pitcher. However an at-bat does not include situations when the batter walks (receives four pitches deemed to be "balls"), the batter is hit by a pitch, or hits a sacrifice (intentionally bats out to get a teammate to score a run).

Examples:
Note: All examples use statistics from the 2011 season - provided by MLB and ESPN. All calculations result in three decimal places.

Matt Kemp, Los Angeles Dodgers: 195 hits in 602 at bats
BA = 195 / 602 = .324

Evan Longoria, Tampa Bay Rays: 118 hits in 483 at bats
BA = 118 / 483 = .244

SLG: Slugging Percentage

SLG = TB / AB = (singles + 2 * doubles + 3 * triples + 4 * home runs) / AB

The higher the better.

TB = total bases, a weighted sum of hits

Matt Kemp: 353 total bases in 602 at bats
SLG = 353 / 602 = .586

Evan Longoria: 239 total bases in 483 at bats
SLG = 239 / 483 = .495

ERA: Earned Run Average

ERA = 9 * ER / IP

The lower, the better.

ER = earned runs scored, in this case, by the opponent. This does not include any runs scored by "errors".

IP = innings pitched. Innings are counted by outs. So if a pitcher threw for six innings and got two outs in the seventh inning, the pitcher has pitched for 6 2/3 innings.

Caution: For IP, some statisticians use shortcut notation. For an IP listed as n.1, it means n and 1/3 innings. (n is a number). If the IP is listed as n.2, it means n and 2/3 innings. Example: A listed IP of 233.1, it means 233 1/3.

Clayton Kershaw, Cy Young Award Winner, Los Angeles Dodgers: 59 earned runs allowed in 233 1/3 innings pitched.
ERA = 9 * 59 / (233 1/3) = 2.276

Chris Carpenter of the 2011 World Series Champions St. Louis Cardinals: 91 earned runs in 237 1/3 innings pitched.
ERA = 9 * 91 / (237 1/3) = 3.451

K/9: Strikeouts Per 9 Innings Pitched

K/9 = 9 * K / IP

The higher, the better.

K = strike out. A pitcher gets this when the pitcher gets the batter to swing and miss on a pitch which results in Strike 3 (symbolized by a forward K), or the pitcher throws the ball to a batter's strike zone but the batter does nothing and is thrown out on Strike 3 (symbolized by a backwards K). Any batter who gets Strike 3 is out.

Per ESPN, Clayton Kershaw's K/9 for 2011 was 9.57 while Chris Carpenter's was 7.24. A K/9 above 9 is considered excellent.

RC: Runs Created (Bill James)

RC = (TB * (H + BB)) / (AB + BB)

The higher the better.

BB = base on balls. A BB is earned when a hitter takes a pitched deemed Ball 4 (the pitcher missed).

This is an estimate of runs created and not a count of the number of runs the player scored.

Paul Konerko, Chicago White Sox: 281 total bases, 163 hits, 77 walks in 543 at bats
RC = (281 * (163 + 77)) / (543 + 77) = 108.774 (estimated 109 runs created)

RBI: Runs Batted In

Commonly known as "ribbys", a batter gets an RBI every time the team scores a run that do not result from "errors". A batter can get up to four RBIs every time the batter is at bat.

Example: A batter has teammates at second and third base. The batter hits a double going to second base, allowing both teammates to reach home base. The batter scores 2 RBIs.

WHIP: Walks and Hits Per Innings Pitched

WHIP = (BB + H)/IP

The lower the better, real good of WHIP is below 1.

C.J. Wilson, was with the Texas Rangers in 2011, now with the Los Angeles Angels of Anaheim in 2012: 74 walks (BB), 191 hits allowed, 233 1/3 innings pitched
WHIP = (74 + 191)/(233 1/3) = 1.187


WAR: Wins Above Placement

Thankfully this is not a measurement of a baseball player's ability to use a weapon. WAR is an encompassing statistic of a player's contribution both offensively and defensively. You may have seen WAR graphs on various sports web sites. Generally, if your WAR is above 8, you are MVP material. If your WAR is around 5, you are an All-Star. If your WAR is around 2, you're an average starter. WAR at 0 and... you will most likely soon to be replaced with a minor leaguer.


These are just some of the statistics that baseball uses. Now it's time to go grab a soda and a hot dog - PLAY BALL!

Source:

MLB Clubhouse - Glossary Page

This blog is property of Edward Shore. © 2012