Can someone explain or confirm this 11-year "controlled" contract stuff? I never heard of such a thing before!
Well, a high school player signs, and they have to spend 5 seasons on the roster at which point they are a 40 man/rule 5 candidate. This is where Stewart currently sits. Without the 40 man guarantee, he can become a minor league FA in one or two more years, at which point, he can do exactly what he wants.
Once on the 40 man, you have 3 seasons of options where you could theoretically sit in the minors before being a FA followed by approximately 6 seasons before hitting major league FA.
I'm guessing 11 came in the form of the first 5 years followed by 6 years of service time. It ignored option years or minor league FA requirements which could lengthen that time (as an example, the Twins could add Stewart to the 40 man next year and start that clock in 2019). It's an estimate, and to be honest, not a very good one based on questionable logic without any documentation on what the contract actually says. The contract likely specifies how long Stewart must play to keep his bonus (unless released of course). It also likely clearly spells out just how the Twins/Stewart can part ways.