Editing Simpson's paradox (section)

===Batting averages===
A common example of Simpson's paradox involves the [[batting average (baseball)|batting average]]s of players in [[professional baseball]]. It is possible for one player to have a higher batting average than another player each year for a number of years, but to have a lower batting average across all of those years. This phenomenon can occur when there are large differences in the number of [[at bat]]s between the years. Mathematician [[Kenneth A. Ross|Ken Ross]] demonstrated this using the batting average of two baseball players, [[Derek Jeter]] and [[David Justice]], during the years 1995 and 1996:<ref name="RossBaseball">Ken Ross. "''A Mathematician at the Ballpark: Odds and Probabilities for Baseball Fans (Paperback)''" Pi Press, 2004. {{isbn|0-13-147990-3}}. 12–13</ref><ref>Statistics available from [[Baseball-Reference.com]]: [https://www.baseball-reference.com/j/jeterde01.shtml Data for Derek Jeter]; [https://www.baseball-reference.com/j/justida01.shtml Data for David Justice].</ref>

{| class="wikitable" style="margin-left:auto; margin-right:auto; border:none;"
|-
! {{diagonal split header|Batter &nbsp;|Year}}
! colspan="2" | 1995
! colspan="2" | 1996
! colspan="2" | Combined
|-
| Derek Jeter
| 12/48
| .250
| 183/582
| .314
| 195/630
| '''.310'''
|-
| David Justice
| 104/411
| '''.253'''
| 45/140
| '''.321'''
| 149/551
| .270
|}

In both 1995 and 1996, Justice had a higher batting average (in bold type) than Jeter did. However, when the two baseball seasons are combined, Jeter shows a higher batting average than Justice. According to Ross, this phenomenon would be observed about once per year among the possible pairs of players.<ref name="RossBaseball"/>