I absolutely understand what you are saying. This is a well thought out post, and I have some of the same thoughts. Unfortunately, it can be difficult to be 100% certain before a decision has to be made, and either choice holds the potential to handcuff a team for several years if it is the wrong one.
I agree with that.
If we wait to pay him next year, he could have a great season that drives up his price and then never repeat it again. However, I do think the evidence would be there that he can put together those kinds of seasons.
If we pay him this year, we save some and it could pay off immediately or even with a mediocre 2019, it could still pay off eventually. Or he may never live up to the deal.
With most players, I probably lean toward not paying them until you have to because so many things can happen. In such a violent game, an injury could end a career in a moment, so why give a player more millions than you have to unless it benefits the team in savings now? That may seem harsh, but it's a practical side of the business.
Then, the other side of it is what I mentioned. There's a lot of guaranteed money that gets put into a player, so you better feel ,as close as you possibly can, guaranteed of success. We've seen in the history of our team some extensions given to players that did not turn out well (and, of course, there are some that did).
I guess it would be fair to say I'm not really an advocate of giving any player a long-term deal until you have to. The only player I would consider doing that with this year is Cooper because of how much he is set to make this year being a factor. We can cut that $14 million down and roll over the money. The rollover from that deal as well as not working out any other extensions this year can be used to help pay deals we have to pay next year.