League Batting Average?

My objective was to compare batters based on percent difference from league average.  So all I needed was a useful common league stat, in this case batting average (BA).  Then the fun began.

Click link to view data and graph.


For Derek Jeter read Yankees.  As mentioned in recent posts: "baseball-reference.com definition of lgBA: a league average (non-pitcher) would have had in the same park(s)."

baseball-reference.com has Advanced Batting under "More Stats", which include the season lgBA, league BA.  I had noticed significant differences between the lgBA for common seasons for Willie Mays and Hank Aaron.

I decided to select an American League (Conference since 1994) batter because pitchers do not bat and compare his lgBA to the league BA as defined as Hits/AB (at bats).  Here is the link with the traditional BA:

http://www.baseball-reference.com/leagues/AL/bat.shtml

I put league BA from Jeter's Advanced stats and the AL into a spreadsheet to compare and create a graph.  Obviously, the there are differences just as I had noticed for Mays and Aaron.

And I thought that BA would be a nice simple comparison to start with.  I filled out an inquiry at baseball-reference.com asking for clarification but have not received a reply.

Year  Jeter AL
1995 0.269 0.270
1996 0.278 0.277
1997 0.271 0.271
1998 0.268 0.271
1999 0.273 0.275
2000 0.275 0.276
2001 0.268 0.267
2002 0.264 0.264
2003 0.265 0.267
2004 0.268 0.270
2005 0.266 0.268
2006 0.277 0.275
2007 0.272 0.271
2008 0.272 0.268
2009 0.273 0.267
2010 0.267 0.260
2011 0.265 0.258
2012 0.258 0.255