wOBA





In baseball, wOBA (/wʌ-bɑː/, or weighted on-base average)[1] is a statistic, based on linear weights,[2] designed to measure a player's overall offensive contributions per plate appearance. It is formed from taking the observed run values of various offensive events, dividing by a player's plate appearances, and scaling the result to be on the same scale as on-base percentage. Unlike statistics like OPS, wOBA attempts to assign the proper value for each type of hitting event. It was created by Tom Tango and his coauthors for The Book: Playing the Percentages in Baseball.[3]




Contents






  • 1 Usage


  • 2 Current Formula


  • 3 Scale


  • 4 Original Formula


  • 5 Citations


  • 6 References





Usage


In 2008, sabermetrics website FanGraphs began listing the current and historical wOBA for all players in Major League Baseball.[4] It forms the basis of the offensive component of their Wins above replacement (WAR) metric. Sites such as The Hardball Times have studied wOBA and found it to perform comparably to or better than other similar tools (OPS, Runs created, etc.) used in sabermetrics to estimate runs.[5][6]The Book uses wOBA in numerous studies to test the validity of many aspects of baseball conventional wisdom.


The benefit of wOBA compared to other offensive value statistics is that it values how the runner reached base, not just if they reached base.[7] Events like Home Runs, walks, singles, etc. are given their own weight (or coefficient) within the linear formula. The coefficients change each year[8], and are based on how often the specific event occurs in Major League Baseball over the course of a season.


Mathematically, we can use wOBA to infer a few more things about a player's production and baseball as a whole. When using the formula (shown below), the numerator side on its own will give us a prediction of how many runs a player is worth to his team.[9]



Current Formula


Per Fangraphs[10], the formula for wOBA in the 2018 season was: [8]


wOBA=(0.69∗NIBB)+(0.72∗HBP)+(0.88∗1B)+(1.247∗2B)+(1.578∗3B)+(2.031∗HR)AB+BB−IBB+SF+HBP{displaystyle wOBA={frac {(0.69*NIBB)+(0.72*HBP)+(0.88*{mathit {1}}B)+(1.247*{mathit {2}}B)+(1.578*{mathit {3}}B)+(2.031*HR)}{AB+BB-IBB+SF+HBP}}}{displaystyle wOBA={frac {(0.69*NIBB)+(0.72*HBP)+(0.88*{mathit {1}}B)+(1.247*{mathit {2}}B)+(1.578*{mathit {3}}B)+(2.031*HR)}{AB+BB-IBB+SF+HBP}}}


where:




  • AB = at bat

  • BB = Base on balls

  • IBB = Intentional base on balls


  • NIBB = Non-intentional bases on balls


  • SF = sacrifice flies


  • HBP = Hit by pitch


  • 1B = Single


  • 2B = Double


  • 3B = Triple


  • HR = Home run


  • PA = Plate appearance



Scale


There is no widely agreed upon scale for wOBA. This table serves as an aggregate summary of other wOBA scales available online.[9][11]


































wOBA Scale
Classification
Range
Elite
.400 and Above
Very Good
.371 to .399
Good
.321 to .370
Average
.320
Bad
.291 to .320
Very Bad
.290 and below


Original Formula


The formula, as it originally appeared in The Book, is


wOBA=(0.72∗NIBB)+(0.75∗HBP)+(0.90∗1B)+(0.92∗RBOE)+(1.24∗2B)+(1.56∗3B)+(1.95∗HR)PA{displaystyle wOBA={frac {(0.72*NIBB)+(0.75*HBP)+(0.90*{mathit {1}}B)+(0.92*RBOE)+(1.24*{mathit {2}}B)+(1.56*{mathit {3}}B)+(1.95*HR)}{PA}}}wOBA=frac{(0.72*NIBB) + (0.75*HBP) + (0.90*mathit{1}B) + (0.92*RBOE) + (1.24*mathit{2}B) + (1.56*mathit{3}B) + (1.95*HR)}{PA}


where:




  • NIBB = Non-intentional bases on balls


  • HBP = Hit by pitch


  • 1B = Single


  • RBOE = Reached base on error


  • 2B = Double


  • 3B = Triple


  • HR = Home run


  • PA = Plate appearance



Citations





  1. ^ "The Language Of Fangraphs | FanGraphs Baseball". Retrieved 2018-12-07..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output .citation q{quotes:"""""""'""'"}.mw-parser-output .citation .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .citation .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-maint{display:none;color:#33aa33;margin-left:0.3em}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}


  2. ^ "Linear Weights - FanGraphs Sabermetrics Library". www.fangraphs.com.


  3. ^ "wOBA - Weighted On Base Average". www.insidethebook.com.


  4. ^ "The Joy of wOBA - FanGraphs Baseball". www.fangraphs.com.


  5. ^ "The great run estimator shootout (part 1) - The Hardball Times". www.fangraphs.com.


  6. ^ "The great run estimator shootout (part 2) - The Hardball Times". www.fangraphs.com.


  7. ^ "What is a Weighted On-base Average (wOBA)? | Glossary". Major League Baseball. Retrieved 2018-11-09.


  8. ^ ab "Guts! | FanGraphs Baseball". Retrieved 2018-11-09.


  9. ^ ab Rogers, Mike (2010-01-19). "Saber 101: Weighted On-Base Average (wOBA)". Bless You Boys. Retrieved 2018-12-07.


  10. ^ "wOBA | FanGraphs Sabermetrics Library". www.fangraphs.com. Retrieved 2018-11-09.


  11. ^ "The Beginner's Guide To Deriving wOBA | FanGraphs Sabermetrics Library". Retrieved 2018-12-07.




References



  • Tom Tango, Mitchel Lichtman, and Andrew Dolphin. The Book: Playing the Percentages in Baseball. Washington, D.C.: Potomac Books, 2007.
    ISBN 1-59797-129-4.










Popular posts from this blog

Italian cuisine

Bulgarian cuisine

Carrot