Andrelton Simmons is the best defensive player in baseball. He’s the first Brave to win that title by acclamation since the heyday of Andruw Jones, and in related news, Braves pitchers allowed fewer runs per game — 3.38 — than any other team in baseball.

In fact, that’s the third-lowest total in franchise history, behind only 1916 and 1968 — the Deadball Era and the Year of the Pitcher, respectively. It was the lowest total in the major leagues since the 2011 Phillies allowed 3.27 runs a game, and they were led by Roy Halladay, Cliff Lee, Cole Hamels, and Roy Oswalt.

So, how did Minor, Teheran, Medlen, and Hudson turn into Halladay, Lee, Hamels, and Oswalt? Here’s how:

Andrelton Simmons was the Braves’ most valuable player last year, but because defense is less well measured and its value is less well understood than offense, Freddie Freeman came in 5th in the league MVP balloting and got a $135 million contract, while Andrelton finished 14th and has yet to sign a contract. There’s no doubt that the Braves know he’s good. But neither the market nor the voters reward defensive dominance the way it rewards offensive dominance, and they aren’t likely to start doing so any time soon.

(Defense and offense are on different scales. It is possible to create more wins with the bat than with the glove — Simmons was worth 5 dWAR last year while Mike Trout was worth 10 oWAR — but still: the Braves allowed the fewest runs in the league despite surrounding Simmons with Chris Johnson and Dan Uggla on the infield and giving Evan Gattis 47 starts in the outfield.

Of course, he did all that despite doing next to nothing at the plate, and if he learns to hit then he could be the best player in the league. On the other hand, “If he learns to hit” is something people have been saying about Elvis Andrus since he was a 17 year old in the Braves system, and Andrus still managed to sign a $120 million contract a year ago.)

At the plate, Simmons has one very good skill: his contact rate was 21st in baseball last year. And he has another decent skill: his isolated power was sixth among major league shortstops. He isn’t Tulowitzki, but he isn’t significantly less powerful than, say, Asdrubal Cabrera. As I’ve often written, when a guy has decent power and doesn’t strike out, that’s a good sign for his future power production. It means he can generate power without selling out for power.

However, he also has two major weaknesses. One is popping up: his infield fly ball percentage was the highest in baseball last year. Another is plate discipline: his walk rate was 30th-lowest in baseball last year. These two may be related.

His terrific contact rate shows that he isn’t a mindless hacker, but it doesn’t completely make up for it. Simmons managed his terrific contact rate while maintaining league average swing rates. In other words, he swung at the same number of pitches both inside and outside the strike zone as most other players. He made contact more often than they did. But it’s pretty likely that some of that was bad contact: I’d guess that a number of those pop-ups came on pitches he shouldn’t have been swinging at.

Simmons would be a significantly better player if he could take more walks, especially if some of those walks came on pitches that he’s currently turning into outs.

Still, as with Andrus, Andrelton’s glove means that he’ll remain a very good player even if he doesn’t become a significantly better hitter. And, of course, Andruw Jones didn’t significantly improve with the bat after he turned 23. He has the tools to be a very good hitter if he can improve his selectivity at the plate, but that’s easier said than done.

No matter what, we’ll always have this: