Today, you commonly hear about players in the NFL breaking some threshold to unlock incentive bonuses. I want to know when these incentives started to appear in players' contracts and how the incentive system evolved.
For the most part, alot of these bonuses started showing up in the mid-nineties due for the most part to Jerry Jones (owner of the Dallas Cowboys). The salary cap was implemented in the 1994 season to prevent more wealthier teams (i.e. the Dallas Cowboys) from buying a championship team. Agents saw this as an opportunity to benefit the players individually. Although an organization will pay team bonuses (i.e. winning the superbowl) the individual athlete has several bonus options in his contract (i.e. signing bonus, workout bonuses, rushing yards, td's, sacks, interceptions...etc.) These types of bonuses have been increasing in the different types of bonuses as well as the monetary value attached to each one in the past 20 years. Players in the 60's even through the late 80's or early 90's typically just had just a straight contract. This information is aquired by being a die hard NFL fan since I was 7 years old, but I found a website for a reference: http://football.calsci.com/SalaryCap2.html