Any player that is in the Top 30 in the ATP Rankings from the previous year is considered a Commitment Player for the current year.
From the 2013 ATP Official Rulebook, I. ATP Circuit Regulations, 1.07 C:
A 2013 ATP commitment player is any player
positioned in the Top 30 in the ATP 2012 Rankings (singles) as of
November 5, 2012.
The commitment for a commitment player is described in section D. Essentially, the Barclays ATP World Tour Finals is required, if accepted; 8 of the 9 ATP World Tour Masters 1000 tournaments are required (all except Monte Carlo), and 4 of the ATP World Tour 500 tournaments are required.
The commitment for the commitment player is, the singles
event of all ATP World Tour Masters 1000 tournaments for which he is
accepted, the Barclays ATP World Tour Finals (if qualified as a
direct acceptance or designated as the alternate) and four (4) ATP
World Tour 500 tournaments, one (1) of which must be held following
the US Open. For commitment and ranking purposes, the Monte Carlo
Masters 1000 will be included in the minimum requirements for the 500
category. 2013 Davis Cup points may be counted as one (1) of the best
of six (6) in the Emirates ATP Rankings, how-ever, it shall not count
towards the commitment requirement of a commitment player. See page
184 “Ranking Penalty.”
A player can get the number of ATP World Tour Masters 1000 commitment tournaments reduced by meeting certain milestones, based on longevity in the league.
1.08 Reduction of ATP World Tour Masters 1000 Commitment
A. A player’s number of ATP World Tour Masters 1000 commitment tournaments shall be
reduced by one (1) tournament for reaching each of the following
1) 600 matches (as of 1 January of the commitment year);
2) 12 years of service;
3) 31 years of age (as of 1 January of the
If all three (3) conditions are met then the player
has a complete exemption from the ATP World Tour Masters 1000 player
B. A player who is eligible for a reduction of his ATP World Tour
Masters 1000 commitment tournaments must be in good standing with the
ATP in order to receive a reduction of required ATP World Tour
Masters 1000 commitment tournaments.
If a player skips the Barclays ATP World Tour Finals without a valid excuse, they are no longer considered in good standing.
1.09 Unsatisfied Player Commitment Penalties
A. Failure To Participate in the Barclays ATP World Tour Finals
1)If a player qualified for the
Barclays ATP World Tour Finals as a direct acceptance or designated
as the alternate, fails or refuses to participate in this event,
except for bona fide injury or other reason which constitutes good
cause, the player shall not be in good standing.
This section of the rule book does not specify a penalty for skipping other commitment tournaments. The Rankings section of the rulebook reveals the penalty. If the other commitment tournaments are skipped, they are counted against the player for ranking purposes.
IX. Emirates ATP Rankings, 9.03 Emirates ATP Rankings:
A. Commitment Players.
The year-end Emirates ATP Rankings is based on
calculating, for each player, his total points from the four (4) Grand
Slams, the eight (8) mandatory ATP World Tour Masters 1000
tournaments and the Barclays ATP World Tour Finals of the ranking
period, and his best six (6) results from all ATP World Tour 500, ATP
World Tour 250, ATP Challenger Tour and Futures tournaments. For every
Grand Slam or mandatory ATP World Tour Masters 1000 tournament for
which a player is not in the main draw, and was not (and, in the case
of a Grand Slam, would not have been, had he and all other players
entered) a main draw direct acceptance on the original acceptance
list, and never became a main draw direct acceptance, the number of
his results from all other eligible tournaments in the ranking period,
that count for his ranking, is increased by one (1). In weeks where
there are not four (4) Grand Slams and eight (8) ATP World Tour
Masters 1000 tournaments in the ranking period, the number of a
player’s best results from all eligible tournaments in the ranking
period will be adjusted accordingly. Once a player is accepted in the
main draw of one of these twelve (12) tournaments, as a direct
acceptance, a qualifier, a special exempt or a lucky loser, or having
accepted a wild card, his result in this tournament shall count for
his ranking, whether or not he participates.