J.D. proof that one never knows the future

For all the numbers we have now in baseball, for all who now worship at the Church of Analytics, there is still no number or set of numbers that can measure with any certainty what a player can become. So it was with J.D. Martinez, who right now, this minute, is one of the best hitters in the game, but was released by the Astros in Spring Training in 2014.