The history of player pay

Pro owners would certainly pay less if they could and pocket the extra revenue. This would require making the market for player services less competitive. \

The first step to reducing pay involves the entry of new talent into the pro ranks. The reverse-order-of-finish draft was established. (The draft used by NBA)

The impact of draft: part of the value of talent that would have gone to recruiting and signing compensation is preserved for the league.
(All competition over incoming talent is eliminated since incoming players have no choice in signing their first contract)

But the amount preserved for the league seems to be diminishing:
(1) training has become a year-round activity
(2) most of the incoming athletes are simply worth too much to let their services slide for a year

The value that is preserved for the league goes to the owners of the weakest teams in the league.

Typically, weak teams are weak because that is the best that their fans will support (Rottenberg's invariance principle)

The draft reduces competition over players as they enter the league. The second step to reducing pay is the reduction of competition over talent after it has been drafted.

1922, the Federal Baseball decision simply meant that it would be nearly impossible to challenge the reserve clause because the Supreme Court had failed to rule against it.

Free agency actually is limited free agency in all pro sports.

One measure of the amount of player MRP that was kept by owners when the reserve clause was in force is called player exploitation.
formula: (MRP-Actual Salary)/MRP

With dramatic escalation in salaries brought by free agency, risk drove owners and players to long-term contracts.

Shirking actually is an old economic issue falling under the heading of principal-agent problems. 
The economic remedies:
(1)monitoring effect 
(2)strategic player effect (合同年效应) incentive-compatible mechanisms like performance incentives and contingency payments.

Invariance principle: the distribution of talent in a league is invariant to who gets the revenues generated by players; talent moves to its highest valued use in the league whether players or owners receive players' MRPs.
But restrictions on competition do reallocate payments away from players toward smaller-revenue market owners.

The invariance principle predicts that the better players will move to better teams, even if a draft is installed. Larger-revenue market owners will compensate smaller-revenue market owners for talent rather than find the talent on their own. If there were no draft, the players would get the money because they would simply go directly to the teams in higher-revenue  markets and collect the returns in terms of higher staring salaries and signing bonuses.

Trading down draft picks: a team actually trades higher draft picks for lower draft picks. Reason: an owner may not be able to afford to pay signing bonuses.