Saturday, January 21st, 2012

Baseball 101: OPS vs. AVG

Several years ago, someone asked me to write a blog called Baseball for Idiots. While I decided not to go the "idiots" route, I settled upon a Baseball 101 series. In that series I discussed: hitting for the cycle and games back. Then the series came to a screeching halt. So it's time for another installment.

When fans think about hitting, the age-old statistic that comes to mind is batting average. Fans will say something like, "He's batting .300 so he's a solid hitter." During the 1941 season, Ted Williams of the Boston Red Sox became the last Major League player to finish the season with a batting average over .400 for the entire season. Being exact, he finished with a .406 average.

But lately, OPS is emerging as a more relevant statistic. OPS stands for On-base plus slugging. OPS paints a more detailed picture of a hitter's performance. Batting average only takes into account the number of times a batter reaches base safely with a hit. It does not factor in walks and being hit by a pitch. Simply stated, OPS is a player's on-base percentage (OBP) plus their slugging percentage (SLG). It factors in the type of hit. Was is it a single or a home run?

To determine a batter's OBP, add together their total number of hits, walks, and times they were hit by a pitch. Take that number and divide it by at-bats, plus walks, plus sacrifice flies, and times hit by pitch.

To determine a batter's SLG, take their total bases and divide it by at-bats.

Finally, to determine a batter's OPS, take their OBP and add their SLG.

According to Bill James, a baseball historian and statistician, he developed seven categories for hitters using OPS.

Great: .9000 and higher (Babe Ruth - 1.164) (Henry Aaron - .928)
Moderate: .8333 to .8999 (Yaz - 8.41)
Above Average: .7667 to .8332 (Ryne Sandberg - .795)
Average: .7000 to .7666 (Devon White - .739)
Below Average: .6334 to .6999 (Tommy Herr - .696)
Terrible: .5667 to .6333 (Augie Ojeda - .633)
Atrocious: .5666 and lower (Tom Seaver - .429, but he was a HOF pitcher)

Tags:  101, baseball, numbers
1 Comment
Thanks Bill. I never knew how slugging percentage was calculated and never took the time to look it up. I always hated that walks don't count as an at-bat for batting average. I'll have to start paying closer attention to OPS.
jef   Saturday, January 21, 2012
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