Sabermetrics 101 - Module 5 | Smart Fantasy Baseball

Sabermetrics

Linear weights – people have used multiple linear regression in order to determine relative value of baseball events (1B, 2B, 3B, HR, BB, HBP, etc.)
One out is -.25
OPS = OBP + SLG
BRA = OBP * SLG
XRR = (.5 * 1B)+(.72 * 2B) + (1.04 * 3B) +(1.44*HR)+.33*(HBP + BB)+.18*SB – .32*CS-.098*(AB-H)
LWTs = (46 *1B)+(.8 *2B) + (1.02 * 3B) +(1.40*HR)+.33*(HBP + BB)+.3*SB – .6*CS-.25*(AB-H)
- By Pete Palmer
- Measures Runs Above Average
Base Runs, created by David Smyth
- More flexible
- Works across different run scoring environments (might even work in softball)

Think of sophomore slumps and SI cover jinx
Often leads to incorrect interpretation of results
We are often measuring outcomes, not talents or skills
Outcomes are not necessarily perfect depiction of talent. Outcomes can have a heavy element of luck.
Envision a typical scatterplot. Even when there is strong correlation between two variables, there is always error above and below that line of best fit.
Outcomes = Innate Skills & Talents + Error Luck Chance Randomness
- IS&T changes over time, it fluxuates
- ELCR can change the outcome even when IS&T doesn’t change!

Describe TableName – gives output of all field names, types, keys, etc. for the specified table
You can select from two instances of the same table in SQL. For example, you can create one instance of the batting table “b12” where yearID=2012, and select data from that. You can then create a second instance “b13” where yearID=2013, and select data from that. Then use WHERE b12.playerID = b13.playerID to get stats side-by-side for two year.

file.choose() – Opens dialog box in operating system to choose the file to load
DataFrameName[“XXX”] = XYZ, to add a new field called “XXX” to a data set using variable array XYZ
lm(X~Y) – fitting linear models, linear regression of variable x against variable y
boxplot() – creates a box plot that shows min, max, median, and quartiles