Collective Bargaining Agreement:
http://mlbplayers.mlb.com/pa/pdf/cba_english.pdf#search='mlb%20collective%20bargain ing%20agreement'
(1) No Player’s contract shall be renewed pursuant to paragraph
10(a) of the Uniform Player’s Contract in any year for a salary
which constitutes a reduction in excess of 20% of his previous
year’s salary or
in excess of 30% of his salary two years previous.
For the purposes of this section, the “salary” of a Player with a
salary stipulated in paragraph 2 of his Major League contract of less
than the then applicable Major League minimum salary shall be
deemed to be the greater of either (a) the total amount of his actual
baseball salary earnings from Major League Clubs (and from Minor
League clubs if any) in that season or (b) the amount stipulated in
paragraph 2 of his Major League contract for that season.
(2) The term “salary” shall include any salary amounts which
were not paid to a Player for the season by reason of any fine or suspension
which may have been imposed on the Player, or by reason
of any other deduction from salary.
(3) In tendering a contract to a Player pursuant to paragraph
10(a) of the Uniform Player’s Contract, no Major League Club shall
offer a salary which constitutes a reduction in excess of 20% of the
Player’s previous year’s salary or
in excess of 30% of his salary two
years previous.