So I just had an opportunity to have a brief exchange with a fella named Josh Ruffin, who works in analytics for the Minnesota Twins (I am up here for a conference).
I asked him, the information we can access on Baseball Savant, how close is that to the information they have in-house at the Twins, and is there a huge chasm? And to my surprise he replied that the Savant information is not all that far away from what they use. He specifically mentioned that the bat speed data that was recently added to Savant by Baseball was released to the teams and to the public at the same time. And of course, they have greater depth of information, such as Savant information for Dominican Rookie League, that we don’t, and they also have additional things that are proprietary such as biomechanics, which itself may come to Savant in a few years. But by and large, the information on a player’s Savant card is really close to the information they use, and he even said he occasionally looks up an opposing player’s publicly-available Savant card to get a quic overview on the guy.