Please read the following from the rule books:

Only a very few PURE BASEBALL ratings are actually used in the game simulation.

The ratings are included in the game to help managers quickly and easily identify a player's strengths and weaknesses.

The actual statistics are what drives the game in most cases. Example: A pitcher may have a 7.3 pitching rating, but his actual statistics versus the type of batter (RH or LH hitter) he is facing, the batter's statistics, the park effects, and other pertinent factors determine the outcomes.