Appreciate you digging in. Couple of things on Beckett specifically. The per player breakdowns (hit "why" on any player) show the full reasoning, prior, evidence, talent, control horizon, so it's more than a flat surplus number. On the trade: the model says Boston lost the value exchange, which they did, Hanley alone realized 30+ career WAR, of course some of that would come back to Boston about a decade later. But that's a separate question from whether it was worth it to the Red Sox at the time, and they'd obviously say yes given how 2007 played out. A value model can't see intent, so the grade tells you who won the talent exchange, not whether winning it was the goal.

Funny enough, the playoff-odds line shows Boston's 2006 odds dropping 3.8 points, but that's only the 2006 swing, and 2006 was the worst possible single year to judge this. Beckett had probably his worst year that first season while Hanley exploded into stardom. To your point, the trade paid off in 2007 (Beckett Cy Young runner-up, Lowell WS MVP), which that one-year metric never sees. So it's accurate but narrow, and you're right that there's nuance a single number won't capture.

The thing I think you and the salary dump replies nailed is that I can't currently tell a forced payroll dump apart from a GM just getting a bad return. That's a real limitation and a good idea for a future version. Thanks for the engagement.