It wasn't supposed to be like this. I mean, we didn't even think that he was a top 10 fantasy prospect in his own organization. To be fair, the Twins do have a lot of high-end prospects, so he probably would have been in the top 10 in a lot of other systems. But to say that the performance this year of Danny Santana was a bit of an outlier might be understating it just a little. The bigger question at this point though is whether he can produce at a similar level in 2015. Let's take a look at some of the categories to see whether this is true or not.
Santana finished the season with a career high in batting average at .319, substantially higher than his .273 career average in the minor leagues. The batting average on balls in play clearly helped him out there (it was .405), although he consistently has posted BABIPs in the .310-.330 range in the minor leagues, so the dropoff from any regression related to that may not hit as hard as you would expect.
The bigger concern in terms of regression has to be from his batted ball profile. We don't have a ton of this kind of data from the minor leagues, but MLBFarm.com has the information going back to the 2013 season, and at least can give us a little bit of a picture. Santana finished the 2013 season with a 15% line drive rate, 53% ground ball rate, and a 32% fly ball rate, which seems reasonable for a middle infield prospect who has shown a little power, but relies more on his speed to help him provide value. His 2014 numbers don't really line up though, as he posted a 26% LD/45% GB/29% FB split instead.
Real or Mirage: Mirage, but only a partial one. He could reasonably hit .270-.280 with average regression, but his lack of walks (4.4% this year, and not above 6% since 2011) could lead to him being challenged more than was previously the case.
Santana hit seven home runs in just 101 games this year, which would lead me to think he could hit 8-10 over a full season at a quick glance. He also added 27 doubles, helping to further show a hitter with decent power. While he has never hit more than 8 home runs in a full season, a majority of the parks he has played at in the minors trend towards pitcher-friendly rather than hitter. I don't think he hits 8-10 every season, but rather settles in between 5-7 each year.
Real or Mirage: Mirage
Santana scored 70 runs this year in just 101 games played, which would trend out to a 112 run pace for 162 games. It's obviously not as simple as that, but 112 runs scored would have been good for a second-place tie behind Mike Trout and tied with teammate Brian Dozier in the majors. When you dig in a little bit more, it starts to show potential regression for Santana.
Santana scored 63 runs without his home runs, and reached one of the bases (H+BB+HBP-HR) 144 times, which was a 43.8% run conversion rate. That seemed high at first glance, and a deeper look at both the league as a whole (29.4%) and all players this year with >20 SB (used as a rough comparison to players with similar speed), a sample of 38, (36%) leads me to think it's reasonable that he would score closer to the 80-90 range over a full season than 110+. These numbers require a little more historical research to see if this season is an outlier or not, but I think the conclusion still holds as reasonable.
Real or Mirage: Partial Mirage. He should provide value in runs, but you can't assume it will be on the same level on a per-game basis in 2015 as 2014.
Santana stole 20 bases in 24 attempts, good for an 83% success rate. While he has shown solid stolen base production in the minor leagues with seasons of 24, 17, and 30 in his last three full seasons, the success rate has been around 60-65% in all of those years. While it is possible that he has gotten better at reading pitchers' moves in the majors, it seems likely that he would fall back into the 65-70% range over time.
In terms of attempts, Santana reached 1st or 2nd base 137 times, and attempted a stolen base 24 times, good for a 17.5% attempt rate. In the minors, he had been around a 25% attempt rate. It seems like the major league rate is about right, as you would anticipate that with better catchers and pitchers with better moves there would be slightly fewer attempts.
Combined together, I think he can reach 20 steals again on a fairly regular basis, assuming that he hits for a reasonably high average. He does not walk much, and so will need to hit in the .280-.290 range in order to get on base enough to get that many attempts.
Real or Mirage: Real.
Overall, Santana should have a lot of value for fantasy owners in 2015. He qualifies at both shortstop and in the outfield in all leagues, and is capable of providing a batting average above .280 with 80-90 runs, 5-7 home runs, and 20+ stolen bases. That should be right around the end of the top 10 at shortstop, with that additional flexibility built in. We won't know until after the offseason whether it is likely that Santana is plugged in as the everyday shortstop or the everyday center fielder, but hopefully should play both positions enough to retain them both long-term.