Pre 1920 errors

"Allow extra pre-1920 errors -- Before 1920 fielding errors were much more prevelant than they are today. There were sometimes as many as 12 errors committed per game, quite an extraordinary number by today's standards. Due to these extremes we have normalized the pre-1920 teams to 1920 levels which will keep the number of errors under control (this makes for a faster playing game that might be preferred by some). However, for realism sake this allows these teams to commit errors at their historical rate".

Can anyone explain the above paragraph? It is listed on "how to read a hitters card" under the maximum rules section. I guess I am having a senior moment right now because I am thoroughly confused. Thanks to anyone who can help.

Well if old time player were using modern gloves and played on manicured fields that are like pool tables, they would make less errors. Conversely if modern players played with gloves that were nothing more than leather work gloves and on uneven dirt infields with rocks the size of golf balls, they would make more errors. So you have to normalize players to some common era as if they are all playing under the same conditions.

Ed