That site has a lot of dumb edge cases you can exploit to make "fair" trades even though there's no way they can occur IRL. I feel like their model does not value superstar players correctly. Baseball is not just a game of surplus value. An elite 5-7 WAR player getting paid $35 million a year should not be considered neutral surplus value. 7 WAR players don't grow on trees. You also can't just spread his money to 7 different 1 WAR players and consider it the same since roster spots also have value. I feel like the tool is a good place to gauge general value for mid and low market players, but they have no way of actually calculating the true value of a guy like Machado, Harper, Tatis, etc.