As an aside...apparently Tom Tango (who actually posted on this site once or twice) is developing some new defensive metric by using the stat cast data. Hopefully that takes some of the guesswork out of judging defensive value. http://www.fangraphs.com/blogs/a-qa-with-tom-tango-the-new-czar-of-statcast/ TT: For fielding, that one has great potential. Mitchel Lichtman has also been the leader with regards to fielding, but he will be the first to tell you the major problem he’s got is that he doesn’t know the starting position of each fielder. Statcast gives us that. I don’t know how many terabytes of data we get out of Statcast, but 50% of the value will simply be knowing where the feet of all the fielders are, when the pitcher releases the ball. Just by doing that, it would essentially make all other fielding metrics obsolete. Then we can spend the other 99% of the time focusing on all the nuances that we can get out of Statcast that will end up giving us some interesting angles. So, the value is in knowing the starting position, but the fun is knowing all the little things that we watch baseball for