http://glb2.warriorgeneral.com/game/forum/thread/5167449Contracts
Obviously, players all have contracts. Every contract in GLB2 is a one season deal (you can send out extensions once the playoffs start), and there are no trades, though as owner you can cut players without consequence.
Contracts can be either low, medium, or high. Medium contracts are the basic, standard contract. A high contract will make a player gain chemistry points twice as fast, and will also give a +25 bonus to a player’s Heart attribute. Low contracts, on the other hand, cut chemistry gain speed in half and cap total chemistry for a player at 50 (and if you renegotiate someone down to a low contract who had more than 50 chem, it’ll drop down to 50 instantly). In general, you’re going to want to avoid low contracts – you really only need low contracts if your team is going to have more than 2 or 3 superstar players. Your team is usually going to be mostly medium contracts – but you’re going to want to get as many players up to High contracts as possible. You can’t “keep” your money – it’s only used for contracts, so make sure you use up as much cap space as possible with high contracts. In general, you’re going to want your QB and HB with highs, along with whichever players seem to have morale problems.