Which free agent would you sign? Jimmy Butler vs. Khris Middleton

AP Images/Morry Gash

I think there's a two-pronged trick to succeeding in NBA free agency.

First you have to avoid the biggest pitfall of the process, which is to pay someone based on what they've already done as opposed to what they are going to do. It's easy to make the mistake because the player's track record is just that -- a matter of record. Meanwhile the future, as always, is uncertain. Also, the track record matters, because that's all we have when projecting a player forward.

After that, even when you've arrived at an in-house projection you're comfortable with, you have to deal with the second prong: valuation. Given the scarcity, or lack thereof, of a player's future dossier and other market factors, what is that performance going to be worth?

All of this makes free agency more than a matter of "who is better?" because you not only need to find the right guy for your roster in terms of on-court fit, but you have to account for the restricted nature of a player acquisition universe governed by the salary cap and luxury tax limits.

Every dollar overspent is a dollar you can't spend on another player. With that in mind, let's begin our series of "Who's Better: Free-Agency Edition" and compare free agents with similar general profiles. In most cases, it's not difficult to identify which player is "better." Identifying which player teams should actually sign is more nuanced. We'll give it a shot.

Today we begin with wings Jimmy Butler and Khris Middleton