Is he going to put up over a whole season what he has done in his last 81 games? Probably not, almost definitely not. But don't sell him short either, his minor league and college numbers are fantastic.
Here is what I wrote in another thread regarding this topic:
In reference to braun, I am not really sure what you mean by "nothing like what he has done".
In 600ish College at bats he posted about a 1130ish OPS, with 45hrs, and about a .360 average.
This year in AAA.
PA:134 AB:117 Runs:28 Hits:40 Doubles:12 Triples:0 Hrs:10 Rbi:22 Walk:15 SO:11 Avg:.342 OBP:.418 Slug:.701 OPS:1119
Sure as you pointed out, its a "small sample space" of only 134 plate appearances.
In 40 spring training abs he has 5 hrs, and a 1269 ops.
If not for one 200ab stint in A+ Brevard Ct. His minor League OPs would be just about 1050, with power numbers similar to his current major league numbers.(assuming some age appreciation, but not totally out of line.) Even still its .946
Obviously he is exceeding expectations, but there was never any question about his bat, and he has previously put up numbers of the caliber he is putting up now. This definitely isn't JJ hardy who had 1 hr every 50abs in the minors, and a minor league OPS of 737 in over 1100 plate appearances.
Go back and read any of the pre-season blogs/expert columns and Braun was widely considered to be one of the best if not the best/most polished bat in the minors to start the year.
Try this comparison:
G AB R H 2B 3B HR RBI SB CS BB SO AVG OBP SLG OPS
170 645 115 205 40 14 36 129 22 14 62 127 .318 .379 .591 970
199 768 131 240 61 6 42 144 34 12 69 152 .313 .374 .572 946 Braun
Is there a difference here, yeah... most people would probably rather have the guy on top. Also consider that the guy on top is Alex rodriguez. I am not trying to say he is, or will be Arod... of course not, Arod is and will go down as one of the best player ever. Braun does have some SERIOUS skills with the bat though.
Yes I do realize Arod was younger... but Braun definitely wasn't "too old" for his level and advanced very quickly through the minors.
I would probably take him him in the third round, depending on who came off the board.
As noted his Babip is coming down, and is around .370 now which is far more reasonable than it was a month ago. In addition his BB/K ratio is a bit concerning, but he is young still and can improve on that like most young guys with skills do. He also has pretty good speed, making him a reasonable 30/30-40/20 thread.