So you may have noticed that every now and then, a player’s valuation has changed on this site. You might be wondering, “Why?” or “Hey, does that mean I have to go back and redo that trade idea I had last week?” Or: “Is this arbitrary, or is there a good reason for it?” All good questions. And yes, there are reasons for the changes. Four of them, typically: New data. Our formulas rely on publicly available services, such as projection systems and...

Now that BTV has been live for a few weeks, we’ve received a lot of questions and feedback, all of which we appreciate. We’ve also noticed some common patterns in the trade proposals, which we'll work into our answers here. Why do the trade values for stars like Jacob deGrom and Mike Trout seem low? Generally speaking, trade value is synonymous with surplus value, which, as we explain here, is the player’s adjusted field value minus the salary. Sure enough, that’s...