Well I figured out how he did it. I've been using Gilmore an example.
Using Overthecap.com or spotrac they are the same this is what the contracts says
http://overthecap.com/player/stephon-gilmore/255
Year/Base Salary+Roster Bonus/Prorated Singing Bonus
2017: 4.5M+500K/3.6M
2018: 8.5M+500k/3.6M
2019: 9.5M+500k/3.6M
2020: 10.5M+500k/3.6M
2021: 11.5M+500k/3.6M
Total 44.5M base salary + 2.5M Roster bonus = 47M total salary and signing bonus of (3.6Mx5 years)= $18M
So I made that contract in Madden with Total salary as 47M, Singing Bonus as 18M over 5 years, The cap numbers are very close to real life.
Real Contract
2017 8.56M
2018 12.6M
2019 13.6M
2020 14.6M
2021 15.6M
Madden Contract
2017 8.18M
2018 9.74M
2019 11.8M
2020 14.4M
2021 17.9M
Year one in Madden is very close to real life. Year two and three are a little off but you pay that difference in year five. Year four is very close to real life.
Overall this is how Shooter McGavin works the contracts in Madden. With so much cap space increase in the game it isn't a big deal with year five being a few million more than real life. At that time you're probably going to get a new player and release him any ways.