Maris was last among qualifiers in the AL in batting average on balls in play with .209 in 1961 and the next lowest was .244

Roger Maris had the lowest batting average on balls in play of his career in 1961 at .209 (league average was .275). The next lowest BABIP for Maris was .236 in 1958. Career BABIP was .254. Maris was last among qualifiers in the AL in 1961 and the next lowest was .244. All data is from Baseball Reference and Stathead.

Maybe he hit lots of fly balls that year which were easily turned into outs (when they stayed in the park). 

 

I found the BABIP of all 47 cases of a guy hitting 50+ HRs in a season.  Maris had the lowest of that group (again, .209). The next lowest was Jose Bautista at .233

So Maris was .024 lower than the next lowest guy. I also found the difference in BABIP between each rank. Ruth in 1920 was the highest with .364 and then Ruth 1921 was next with .363. So a difference of .001. I calculated the difference in BABIP like that for all the ranks and the next largest difference after the .024 difference between Maris and Bautista was .010, which occurred 3 times. The average difference was 0.00337. Most are below .005. So Maris is an outlier here.

If we don't include Maris, the average difference between ranks is 0.00291.

 

The standard deviation of that group for BABIP was .037 (including Maris). Since .024/.037 = .648, that means that Maris is almost 2/3 of a standard deviation below the next lowest guy.

The simple average of the 47 BABIPs was .302. So Maris was about 2.5 standard deviations below that. So, in this one way, Maris's 1961 season is unique among 50+ HR hitters.

In 1961, the standard deviation of BABIP for qualifiers was .027. Maris was .035 below the next lowest guy. That is 1.3 standard deviations. The next highest difference between ranks was .025, then .021, then .012. So again, like with the 50+ HR hitters, Maris really sticks out.

I also looked at all the guys who hit 50+ HRs in a season since 1988, the first year when BB Ref has batted ball type percentages. 30 guys were on the list. The correlation  between FB% and BABIP for that group was -0.087. It makes sense that the more FBs you hit the lower your BABIP. But for this group of elite HR hitters the effect is pretty weak.

So far this year for all qualifiers in the AL, the correlation between FB% and BABIP is -0.19 and last year it was -0.23. So maybe the effect is actually a bit stronger than the -0.087 shows. But still not much.

 

The simple averages for FB% and BABIP for this group of 30 are 34.56% and .298, respectively.

For the 50+ HR hitters, the five highest FB%'s were 

Player	HR	Year	FB%	BAbip
Barry Bonds	73	2001	44.4	0.266
Mark McGwire	52	1996	43.3	0.308
Mark McGwire	65	1999	39.5	0.250
Jim Thome	52	2002	38.6	0.319
Aaron Judge	62	2022	38.3	0.340

It does not look like the BABIPs are especially low here. 3 of them are above the average of .298 for the 50 HR guys. And they are allow well above Maris's .209.

Now the five lowest FB%s.

Player	HR	Year	FB%	BAbip
Alex Rodriguez	54	2007	30.5	0.309
Pete Alonso	53	2019	28.3	0.280
Sammy Sosa	66	1998	28.3	0.321
Albert Belle	50	1995	26.4	0.293
Giancarlo Stanton	59	2017	22.4	0.288

These BABIPs are not especially high. It looks like a low FB% for a power hitter does not necessarily translate into a high BABIP.

Maybe Maris had such a low BABIP in 1961 because he hit so many flyballs. But other data does not suggest a pattern that would support that conclusion.