In order to appreciate that journey that Gary Sanchez has taken to the show, one must understand just how long the road has been. The Yankees (probable) back-up backstop was signed in June of 2009, at the age of 16. He made his first appearances on Baseball America's top-100 list heading into the 2011 season, ranking 30th, and helped many Yankees fan cope with the Jesus Montero for Michael Pineda swap - and if that doesn't date Sanchez as a prospect, then I don't know what will. He appeared in BA's top-100 for four years in a row, before falling out of favor with many over the course of the 2014 season, prompting articles such as this. Sanchez was ranked 35th by BA heading into 2014, and fell off the list entirely afterward (he was ranked in the top-100 by both MLB.com and Baseball Prospectus and fell out of both, as well).
And then 2015 happened.
This past season, Sanchez batted .262/.319/.476 with 12 HR (127 wRC+) in 58 games at Double-A, and .295/.349/.500 with 6 HR (145 wRC+) in 35 games at Triple-A. He followed that up with a stellar performance in the Arizona Fall League, hitting .295/.357/.625 with 7 HR (159 wRC+), leading the league in XBH, HR, and RBI. In short, Sanchez was brilliant in 2015, showcasing the bat speed and plus raw power that, when partnered with his position, made him one of the best prospects in the game in the not so distant past.
Even so, it's the "when partnered with his position" modifier may well be the most important part of it all.
Like Montero before him, Sanchez has long been maligned for his subpar defense, and for good reason. For the better part of his professional career, Sanchez was a stiff, rough-handed receiver that struggled to block balls in the dirt. To many, it wasn't a matter of if he moved out from behind the plate - it was a matter of when. Sanchez's offensive profile is good for most any position, but a shift from catcher to one of the 1B/LF/DH trifecta would severely damage his stock.
Luckily for Sanchez, 2015 wasn't just a career year offensively, as the resurgent prospect drew almost universal praise for improved defense last season. John Sickels believes that he can stick behind the plate, and went so far as naming him the Yankees top prospect, and the Baseball Prospectus team noted that more and more people see him as a catcher. And isn't just the scouts, either. Baseball Prospectus' new catching metrics for the minor leagues suggest that Sanchez is a mostly average catcher (analysis courtesy of River Ave Blues). In fact, he may have been a tick better than average last year.
For fantasy purposes, of course, you had me at "he can stick behind the plate." Whether or not he can play anything better than passable defense is immaterial so long as he qualifies at catcher, where he has the offensive tools to rank among the five best players at the position. ZiPS projects Gary Sanchez as a roughly league-average hitter this year (.240/.291/.434, 315 wOBA, 99 OPS+), with the potential to crank out 20 HR in just 446 PA.
And that is just scratching the surface of his considerable ceiling.
Sanchez has the potential to hit for a solid average and above-average to plus power - a combination that should put him in the middle of a lineup, providing for plenty of opportunities to both score and drive in runs. Not many catchers can hit .260 to .270 with 20-plus home runs nowadays (only one did last year, and only two more hit over twenty bombs). As long as he stays behind the plate, he should be an elite fantasy commodity.
I am often hesitant to throw a comp onto a player, but I think it is fairly simple with Gary Sanchez (at least insofar as statistics are concerned) - Mike Napoli. The walks may not be there in the minors, but Sanchez is not an impatient hitter, nor does he have poor strikezone judgment. His approach can be described mostly as 'controlled aggression,' and I would be surprised if his walks and strikeouts did not jump up at least a bit once he grows accustomed to the Majors. If the walks don't show up, he can still make enough contact and hit for enough power to have a ton of value (e.g., Evan Gattis in 2014).
The only issue with Sanchez in 2016 is that, barring an injury or a trade, he isn't likely to be more than Brian McCann's back-up. That makes him a better target in keeper leagues, but I wouldn't sleep on him this year, given McCann's age and mileage. And when it comes to Sanchez's bat, it's a matter of when, not if.