jboverfelt

; clojure has all the basic datatypes - string, double, float, boolean
; it also has symbols, keywords, and nil instead of Java's null

; a symbol (an identifier that usually refers to something else
'test

; a keyword (generally used in maps and for "enum" like values)
:foo

; Data Structures

jboverfelt

(defmacro foreach [& body] 
  (let [parts (partition-by #{'in 'do} body)
         [v _ lst _ forms] parts]
  `(doseq [~(first v) ~(first lst)] (do ~@forms))))

jboverfelt

(defmacro do-until [& clauses]
  (when-let [[first second & rest] clauses]
    (list 'when first
      (if second
        second
        (throw (IllegalArgumentException. "do-until requires an even number of forms")))
      (cons 'do-until rest))))

jboverfelt

The dust from the winter meetings is settling, and GMs across the league are giving us a better picture of what their Spring Training rosters might look like. Everyone is off trying to find the 2014 version of Chris Davis or Jean Segura, but I’d like to suggest we take a break from that for a moment. Instead, let’s focus on something more sinister (MUHAHAHA!): who will be the biggest bust of 2014?

In a Fangraphs article last year, Bill Petti laid out a novel framework for predicting player collapses based on a few metrics. I won’t repeat his research here, but I encourage you to check out that article. I’ve decided to focus on one indicator he targets: Z-Contact%. This is the percentage of pitches in the strike zone that a hitter makes contact on when swinging. A decline here could indicate that a hitter is losing bat speed, which could cause a drop in AVG among other things.

Large Z-Contact% decliners 2012-2013: