Below is from the contract rules. If you make a $10m bid the contract can be $10m for 1 year, $5m for 2 years, or $3.4m for 3 years. A 4 year contract must be at least $5.1m per year and a 5 year contract must be at least $10.1m per year. You must have salary cap space to cover all bids made:
Contract Terms
Except for any contract inherited in 2013, all contracts must be no longer than five years. Also, for a given salary, all contacts have term limits (max years contract can be per the salary) as provided below.
<= $1m, 2 years
$1.1m - $5m, 3 years
$5.1m - $10m, 4 years
> $10m, 5 years (the overall limit)