If you've been around CougCenter for any length of time, you know of our affinity for rate statistics and disdain for raw data. Normally, we reserve our ire for antiquated basketball statistics, since our two main sports we cover are football and hoops, but with the emergence of the baseball team and the subsequent analysis that requires, here's your quick guide to some stats we're referencing. Definitions are from The Hardball Times glossary.
What's up with those slashes? You might see us say a guy has a line of .333/.405/.556. The first number is his batting average, the second is his on-base percentage and the third number is his slugging percentage. It's designed to give a well-rounded view of the hitter.
Batting Average (BA): Hits divided by At Bats. The college baseball average from 2006-08 was.293.
- On-base Percentage (OBP): The proportion of plate appearances in which a batter reached base successfully, including hits, walks and hit by pitches. OBP is also a powerful performance metric when interpreted as the percentage of times the batter didn't make an out. The college baseball average from 2006-08 was .369.
- Slugging Percentage (SLG): Total Bases divided by At Bats. Singles are worth one base, doubles worth two, etc. The college baseball average from 2006-08 was .425.
- This leads to On-base Plus Slugging (OPS): A crude but quick measure of a batter’s true contribution to his team’s offense. Just add together OBP and SLG. The college baseball average from 2006-08 was .795.
Here are some other stats we reference:
- Earned Run Average (ERA): Number of earned runs allowed divided by innings pitched multiplied by nine. It's a rather terrible measure of a pitcher's actual effectiveness (as explained here), but it's the best we can do until someone starts posting more advanced pitching metrics for college baseball. The college baseball average from 2006-08 was 5.27. (Bet you didn't think it was that high, did you?)
- Isolated Power (ISO): Measures the "true power" of a batter. The formula is SLG-BA. The college baseball average from 2006-08 was .132.
- Strikeout Percentage/Strikeout Rate (SO%): On offense, how often a batter strikes out when coming to the plate; for a pitcher, at what rate he strikes out the batters he faces. Strikeouts divided by total plate appearances. The college baseball average from 2006-08 was about 16 percent.
- Batting Average on Balls in Play (BABIP): This is a measure of the number of batted balls that safely fall in for a hit (not including home runs).
Where did you get those averages from? We got the raw CSV data from here (seriously, how did anyone ever do research before the Internet?), imported it into Excel (same question regarding computers), and did the calculations ourselves from there.
There was one minor snag -- some of the player data had missing elements (such as total at bats or home runs or whatever), so we elected to just remove those players from the overall data set. We're pretty sure it didn't skew the data much; for the hitters, we removed just 748 of the original 16,162 player entries (4.6 percent), and for the pitchers, we removed just 538 of the original 11,743 player entries (also 4.6 percent).
We think using around 95 percent of player performance gives us a pretty good picture of national averages, don't you?