Sunday Morning Sabermetrics: BABIP, ISO, and wOBA

Image Credit: Fangraphs

Last week on Sunday Morning Sabermetrics, we covered the Slash Line, the basic offensive rate stats used to evaluate players more effectively than the traditional batting average stat can accomplish. This week, we delve deeper into offensive rate stats, introducing even lesser known stats to further understand the quality of a player’s offensive contributions. These are Batting Average on Balls in Play (BABIP), Isolated Power (ISO), and Weighted On-Base Average (wOBA).


BABIP = (Hits – Home Runs)/(At Bats – Strikeouts – Home Runs + Sacrifice Flies)

ISO = Slugging Percentage – Batting Average

wOBA = (.69(BB – IBB) + .72(HBP) + .89(1B) + 1.27(2B) + 1.62(3B) + 2.1(HR))/(AB + BB – IBB + SF + HBP)


The complete spreadsheet for all major leaguer's 2016 BABIP, ISO, and wOBA scores is available here:

Stats are as of games before Saturday, June 25th. These stats are not available on, so be sure to check out the above spreadsheet!


Batting Average on Balls in Play is a way to measure how often the balls a given hitter puts into play end up going for hits rather than outs at the hands of the defense. The denominator of the above equation represents the number of times a hitter put the ball into play. This is official at bats less strikeouts and home runs (balls not put into play in the total pool of at bats), plus sacrifice flies (balls put into play but not official at bats). The numerator represents the number of times the balls in play were hits rather than outs. This is hits less home runs (included in hits but not balls in play, since no fielder had a chance to make the play).

In a small sample size, BABIP can tell us which players are likely to progress or regress based on bad or good luck, respectively. If a player has an excessively high BABIP over a small stretch of games, it is likely due to balls just falling in the right places for hits. Over time, luck more or less evens out among all players, and the players with the highest BABIP have that because of other factors, mainly exit velocity and speed. Players who tend to hit with higher exit velocity will get on base more on balls they put in play, since balls hit harder are harder to field. Also, speed helps, since faster runners will leg out more infield hits, improving their BABIP scores.

As of Saturday, June 25th, the top 5 highest BABIP scores in the majors are Starling Marte (PIT, .407), David Freese (PIT, .393), Jonathan Villar (MIL, .392), Xander Bogaerts (BOS, .392), and Ian Desmond (TEX, .386). One commonality within this group is high raw batting averages, .329, .291, .292, .349, and .321, respectively. A high batting average, combined with low home run totals (6, 6, 6, 9, 12, respectively), will result in a high BABIP. Also key to this group, with the exception of Freese, is speed. The other four players run very well and can beat out infield hits more than most other players in the league.


Isolated Power is a simple statistic to calculate, merely Slugging Percentage less Batting Average. This measures a player’s ability to hit for extra bases. Players with small ISO scores are mostly singles hitters, while players with high ISO scores will be more likely to hit for extra bases, given that they will get a hit. ISO does not take into account the frequency with which players get hits, instead, it is a way to measure that when a player does get a hit, the likelihood that it will go for extra bases.

The top 5 highest ISO scores in the majors are David Ortiz (BOS, .351), Adam Duvall (CIN, .332), Jay Bruce (CIN, .300), Manny Machado (BAL, .295), and Nolan Arenado (COL, .295). These five players are all tremendous power hitters (18, 21, 16, 18, and 21 home runs), and have high OPS+ scores as well (191, 129, 138, 160, and 138).


Weighted On-Base Average is an improved version of the On Base Plus Slugging statistic, treating a hitter’s ability to get on base as more important than his ability to hit for power, which it is. Using ratios derived from thousands upon thousands of games worth of data, walks (disdaining intentional walks because these hardly reflect the ability of the hitter in that particular at bat), hit by pitches, singles, doubles, triples, and home runs are valued to come up with a weighted on-base average for that player. Tom Tango developed the wOBA stat and to this day is one of the most important standard batting statistics used to evaluate hitters. To prove that, below is the top ten highest wOBAs in baseball so far this season, and it would not make a bad list of the top ten hitters in baseball so far in 2016 in the opinions of analysts, fans, coaches, and scouts:

1.     David Ortiz (BOS, .466)

2.     Manny Machado (BAL, .421)

3.     Matt Carpenter (STL, .416)

4.     Michael Saunders (TOR, .415)

5.     Daniel Murphy (WSN, .415)

6.     Jackie Bradley Jr. (BOS, .415)

7.     Jose Altuve (HOU, .413)

8.     Nolan Arenado (COL, .413)

9.     Paul Goldschmidt (ARI, .413)

10.   Josh Donaldson (TOR, .411)


Two players who are notoriously absent from the above list are Anthony Rizzo (CHC, .410, 12th) and Mike Trout (LAA, .400, 16th). This highlights a major shortcoming of all three stats we talked about this week. Neither BABIP nor ISO nor wOBA take into account the home ballpark a hitter plays in. Angels Stadium and Wrigley Field are both notoriously pitcher-friendly, which means that if Rizzo and Trout played in more hitter-friendly parks as Fenway Park or Camden Yards, their raw stats would be higher (more home runs with smaller dimensions, etc.) and may have placed them into the Top 10 for wOBA.

One player who many of you feel deserves a spot in the top 10 is Xander Bogaerts (BOS, .395, 18th). Bogaerts is tied with Daniel Murphy for the highest batting average in baseball, .349.  However, Bogaerts has fewer total bases (155) than Murphy (157) despite recording more at bats (307) than Murphy (272). Murphy has a tendency to hit for extra bases more so than Bogaerts, lifting Murphy’s wOBA over that of Bogaerts. Also not helping Xander’s case for the top 10 is that he plays in one of the most hitter-friendly parks in baseball in Fenway Park, giving him an advantage over most other hitters in terms of the non-ballpark adjusted wOBA stat.


Previous Sunday Morning Sabermetrics articles:

June 5th: Pythagorean W-L

June 12th: Wins Above Replacement

June 19th: OBP/SLG/OPS/OPS+


Next Week (July 1st): We cover the cumulative offensive stats, Runs Created, which takes into account the all-around abilities of the hitter on the offensive side of the game and determines how many runs that player contributed to the team. An improved version of Runs Created, Adjusted Weighted Runs Created (wRC+) will also be covered. This article will be published in the early morning of Friday, July 1st, instead of the usual early Sunday morning.

Share This Article

Past News

Search Archive »

Browse by Year »


Browse by Month »

September 2023
August 2023
July 2023
June 2023
April 2023
March 2023
February 2023
December 2022
November 2022
September 2022
July 2022
June 2022
May 2022
April 2022
March 2022
February 2022
January 2022
December 2021
September 2021
August 2021
July 2021
June 2021
May 2021
April 2021
March 2021
January 2021
December 2020
November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
March 2020
February 2020
October 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
August 2018
July 2018
June 2018
April 2018
March 2018
February 2018
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
November 2016
September 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
September 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
November 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
December 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
December 2011

You Tube
Number 11
Number 21
Number 40
Number 42
Number 5
Number 7