Toronto Blue Jays centerfielder Anthony Gose took a major step forward this year with his performance in AA at age 20, showing patience and a little more pop, with a strong .254/.358/.444 line against right-handed pitchers. He does need to improve against southpaws, and his line was boosted by a good home park (especially for left-handed hitters), but given his athleticism and other tools, the hitting line and the improvements in his swing that caused it are really promising.
The Blue Jays had tried to get Gose in the Halladay deal, recognizing that he had tremendous athleticism but no polish to his game, and after acquiring him last summer they spent the offseason working with him on finding more consistent, simpler swing mechanics. Out of high school, Gose started with a wide stance and drifted onto his front foot, almost without purpose, then generated most of the power in his swing with his hands, throwing the bat head at the ball with an inconsistent swing path and finish. Now, he's starting with a narrower base, striding forward to get his swing started, keeping his weight back longer and his back more stable, letting him drive through the ball and generate some power from his hips and legs while maintaining a much more consistent swing.