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Fantasy Category Discussion: Average and On Base Percentage

I'm continuing a series discussing the pros and cons of some controversial fantasy baseball categories. Today it's average and on base percentage.

Dee Gordon is a beast in the average category, but doesn't even crack the top 40 in OBP.
Dee Gordon is a beast in the average category, but doesn't even crack the top 40 in OBP.
Steve Mitchell-USA TODAY Sports

It's a debate that is as old as time, if time started in the 21st century: Average or On Base Percentage, which is the better category for fantasy baseball? Back in the ancient times of yore (you know, the 1980s and 90s), fantasy baseball was 4 x 4 or 5 x 5 in basically all leagues, or so I'm told. That meant R, RBI, AVG, HR, SB for hitters and K, ERA, WHIP, W, and SV for pitchers. 4 x 4 leagues dropped runs and K, in case you were wondering. Many of those categories have been replaced or added to in recent years, and for some good reasons.

Today I continue a series that will hopefully spark some good discussion, both in the comments section and within your leagues. I'm going to look at controversial "new school" categories and their older equivalents and weigh the pros and cons of each. Today's debate gets kicked off with the question: "Is batting average or on base percentage a better rate stat to measure a hitter's contributions?"

On Base Percentage


The easiest positive for using OBP is that it includes the effects of walks. Walks are directly correlated to run scoring, which is kind of the point of baseball. More walks equals more runs, everything else being equal. OBP still includes the affects of balls in play and a high batting average will boost OBP, so average isn't gone.

Hitters that are patient and are skilled at reading pitches are usually very good hitters with good averages, but their batting eye skills are only fully accounted for if you include OBP. Guys like Votto, Harper, and Rizzo are good in any format, but you are selling them short if you don't include their massive OBP values. Including their walks comes much closer to matching their real-world value.


It's not a traditional statistic and doesn't have a long history for comparison. It can overvalue sluggers, especially those that are prone to strikeouts. Guys like Chris Carter and Joey Gallo kill you in leagues with average, which balances out their power advantage (home runs count for runs, RBI, and home runs, so you get a multiplier effect). In OBP leagues, these guys are much less damaging and their power boost becomes more valuable.

If you feel that strikeout-prone hitters should be penalized for striking out so much, OBP leagues are not for you, since most power hitters have decent or good OBPs despite high strikeout totals. Adam Dunn was the poster-child for this issue for many seasons. Walks can also be viewed as "boring" since the ball isn't put into play. Further, walks can be caused by a pitcher that is just wild and have nothing to do with a hitter's skill.



Batting average has been around as long as baseball itself. It has been in fantasy baseball since the beginning. It is easy to calculate and understand and everyone has a good frame of reference for it. Average boosts the value of speedsters, helping them better compete with the big power hitters in fantasy, since they can contribute positively in three categories (runs, steals, average) to match the three power categories (homers, runs, RBI). Average rewards making contact and putting the ball into play. This makes things happen and puts pressure on the defense.


Using average misses out on about 7.7% of the game of baseball. That 7.7% is the league average walk rate. That is a significant portion of offensive baseball. Average devalues hitters that have power and/or speed but strikeout too much. Steven Souza is an example of a guy with power and speed whose strikeouts kill his average. He walks enough to be OK in OBP leagues, though. There are many other examples of guys that contribute in every category but average.

The other big issue with average is that it is very reliant on BABIP and BABIP often involves a lot of luck. Sure, there are fast hitters or hitters that make excellent hard contact that maintain high BABIPs, but most hitters with high BABIPs see regression the next season and the league average is always around 0.300 every year. Therefore, average is partially driven by dumb luck and defensive misplays and not the batter's skill. OBP includes more batter skill by adding in patience.


To better understand this issue with some actual 2015 season data, I put together some tables.

2015 League Averages

AVG OBP Std. Dev Avg Std. Dev OBP
0.254 0.317 0.025 0.035

Top 10 Batting Averages 2015

Name AVG OBP BABIP Avg-league avg AVG OBP-AVG SB
Miguel Cabrera 0.338 0.44 0.384 0.084 0.102 1
Dee Gordon 0.333 0.359 0.383 0.079 0.026 58
Bryce Harper 0.33 0.46 0.369 0.076 0.13 6
Paul Goldschmidt 0.321 0.435 0.382 0.067 0.114 21
Xander Bogaerts 0.32 0.355 0.372 0.066 0.035 10
Buster Posey 0.318 0.379 0.32 0.064 0.061 2
A.J. Pollock 0.315 0.367 0.338 0.061 0.052 39
Joey Votto 0.314 0.459 0.371 0.06 0.145 11
Yunel Escobar 0.314 0.375 0.347 0.06 0.061 2
Jose Altuve 0.313 0.353 0.329 0.059 0.04 38
Average 0.3216 0.3982 0.3595 0.0676 0.0766 18.8

Top 10 OBPs 2015

Bryce Harper 0.33 0.46 0.369 0.143 0.13 6
Joey Votto 0.314 0.459 0.371 0.142 0.145 11
Miguel Cabrera 0.338 0.44 0.384 0.123 0.102 1
Paul Goldschmidt 0.321 0.435 0.382 0.118 0.114 21
Mike Trout 0.299 0.402 0.344 0.085 0.103 11
Andrew McCutchen 0.292 0.401 0.339 0.084 0.109 11
Anthony Rizzo 0.278 0.387 0.289 0.07 0.109 17
Buster Posey 0.318 0.379 0.32 0.062 0.061 2
Michael Brantley 0.31 0.379 0.318 0.062 0.069 15
Prince Fielder 0.305 0.378 0.323 0.061 0.073 0
Average 0.3105 0.412 0.3439 0.095 0.1015 9.5

In the league averages table, you will notice that the standard deviation (a measure for how much spread/variability across the league there is) for OBP is higher than average. This means that the spread in the range of OBPs in baseball is larger than that of average. The batting averages of all hitters are more closely bunched together than OBPs. I'm not sure if this is a "pro" or a "con" for either category, it's just something to note. If you want a stat where having one of the worst players in that stat doesn't hurt you as much, then average would be better. Having a very bad OBP is more of a penalty than a bad average.

Looking at the tables of the top 10 averages and OBPs in 2015, there are a few observations. First, the average BABIP for the first table is a little bit higher than the second. That matches the notion that batting average is more reliant on BABIP. The difference to league average column in both tables shows that once again, the spread of OBP values in the league is greater. The average of the top 10 OBPs is 0.095 better than league average, while the top 10 averages are only 0.068 better than the league.

The assumption I made that average boosts the value of fast hitters also seems correct. Look at the average steals between the two tables. Fast guys have better averages (partially due to their better BABIPs) than guys that walk a lot, on average. In these tables the batting average guys double the steals of the OBP guys. The OBP minus AVG column just shows that the OBP leaders walk a lot more than the average leaders (well, duh).

Guys that hit for a high average are often reliant on balls in play and don't walk much. Of course, there are the absolute studs that show up on both lists like Goldschmidt, Cabrera, Harper, and Votto. This just shows how you can dominate both OBP and AVG if you are very good.

I'll let you make up your own mind about which of these two categories is best. I play mostly in OBP leagues, so I am just more comfortable evaluating players based on OBP. Further, hitters with high OBPs tend to have fewer slumps throughout the year because even if they aren't getting hits, they are still getting walks and contributing to my offensive stats. I've had many occasions where my hitters go 0 for 2 with two walks. That's still a very good OBP of 0.500 but an average of 0.000. It comes down to how you feel about walks and their inclusion in fantasy baseball. I hope this has fueled some thought about this long standing debate. Tschus!