We did the math: Here's MLB's best defender

Javier Báez has been able to create magic on the field for his whole career, but he hasn't always been the best. Now he is.

Báez has always been capable of making the sensational play -- that's why he's so fun to watch -- but he's grown from a whirlwind of a highlight reel into the top-rated defensive infielder in baseball. Statcast debuted its all-new Outs Above Average metric for infield defense this week. El Mago is No. 1.

Best infielders by Outs Above Average in 2019
Javier Báez (SS, CHC): +19
Nolan Arenado (3B, COL): +17
Andrelton Simmons (SS, LAA): +16
Nick Ahmed (SS, ARI): +16
Trevor Story (SS, COL): +15
Matt Chapman (3B, OAK): +14
See the full leaderboard here

That's quite the group to lead. It's full of Gold Glovers, and Arenado, Simmons, Ahmed and Chapman in particular are the perennial elite defenders in the sport. (It's worth noting that this is a counting stat, and Báez only played 130 games in the field last season, although that was 28 more than Simmons).

Statcast has Outs Above Average for outfielders, too. If you combine the leaderboards, Báez stands second overall, behind only Nationals center fielder Victor Robles at +23. But Báez actually has a strong claim to the title of most valuable defender in the sport. Here's why.

As the Cubs' shortstop, Báez has to do tons of different things. He has innumerable responsibilities. He could be playing in the hole one play, up the middle the next, and as the rover in short right field after that. Outfield OAA is based only on making catches, and favors players with pure speed, like Robles, who can just run down more balls than other outfielders. But so much goes into infield defense.

The cool thing about Báez is, he can make any type of play, whether it demands arm, range, reaction, instinct, speed, ball tracking, glovework, quick hands … whatever. Think about all the different ways an infield play can be difficult. You name it, Javy's made it. Playing an elite shortstop in today's game requires unparalleled versatility. That Báez can do everything is what makes him uniquely indispensable, even compared to a top defensive center fielder like Robles.

There's also this: Báez faced the toughest plays of any infielder in baseball, and he still excelled.

Based on the difficulty of the chances he was responsible for, you could expect Báez to make 83% of his plays -- the lowest estimated success rate among MLB infielders. He got the out 88% of the time. (Robles, for comparison, had an expected catch percentage of 87% on balls hit to him.) That means Báez converted 5% more plays above expectation. Among MLB regulars, only Simmons (+6%) was better.

But lest you forget about the importance of the routine play: Báez also made every single one of the 147 plays he faced with a 95%-plus estimated success rate. Contrast that with an infielder who struggled, like Fernando Tatis Jr., who misplayed 10 of those balls, only converting 91% to Báez's perfect 100. Mistakes on routine plays are hugely costly; Tatis ended up with a negative-13 OAA.

So when you see Báez up there in the No. 1 spot, understand that he's harnessed his electricity. Báez hasn't yet won a Gold Glove. He probably should have.

Infield Outs Above Average comes from two basic parts of a play. The first part is the "intercept" -- that's how far the infielder has to go to get to the ball, and how long he has to get there. The second part, for ground balls, is the throw -- its distance, combined with the time a fielder has to make it based on the runner's average sprint speed. An infielder gets a plus or minus based on how hard the play is. For example, if he makes a play he only had a 25% chance of making, he gets +0.75; if he doesn't make that play, he's only knocked -0.25. His total Outs Above Average score is the sum of all those pluses and minuses.

Here's a look at five plays Báez made in 2019. Each one showcases a different skill.

1) Reaction (July 13 vs. Pirates)

Check out this game-ending double play … wow. Báez only had 1.9 seconds to get to this liner up the middle from Kevin Newman, and he was just over 18 feet away. But the lightning reflexes, the perfect dive and the nifty glove flip are why they call him El Mago.

2) Range (April 17 vs. Marlins)

Báez had a little more time to get to this one -- 2.4 seconds -- but he also had 10 more feet to cover. Báez's ability to smoothly range the 28 feet up the middle gave him the time he needed to unfurl a spinning 120-foot throw to nab the speedy Isaac Galloway, who was getting down the line at 30.7 feet per second. For sprint speed -- that's Statcast's baserunning speed metric -- 30-plus ft/sec is elite.

3) Quick hands (May 22 vs. Phillies)

Báez only fielded this ball because David Bote couldn't cut it off at third base. When you field a ball behind your third baseman, that deep in the hole, with a runner as fast as Scott Kingery (who was at 29.1 ft/sec here), chances are you're not getting the out at first. Báez did. He scooped the ball on his backhand and got rid of a throw in just 0.60 seconds -- and he still managed to get 81.0 mph on it. The fast exchange made the play.

4) Command of the field (July 12 vs. Pirates)

Part of being a star shortstop is being a field general. That's what Báez was here. When Adam Frazier skied a popup into shallow left field, Báez covered 101 feet back into the outfield to make the catch, calling off left fielder Kris Bryant. He ended the play 213 feet away from home plate. Just your routine shortstop territory.

5) Arm (June 12 vs. Rockies)

Báez's average max-effort arm strength last season, 88.3 mph, ranked third-highest among regular infielders behind Fernando Tatis Jr. and Carlos Correa. On this play with the bases loaded, Báez charged Ian Desmond's chopper and fired off a 90.9 mph throw to the plate -- in just 0.67 seconds, no less -- to get Charlie Blackmon and keep a run off the board.

Báez did it all. He wasn't even a full-time shortstop until this year, and he wasn't permanently installed there until the Cubs decided early in the season that Addison Russell would not be getting the job back. But Báez's first full year at the infield's premium position turned out to be an ascendance to the top of that position. He was better at shortstop in 2019 than Russell ever was (Russell had a +14 OAA in 2018, and +13 OAA in '17).

He was strong in every direction, on a level most infielders are not. Báez rated as +7 Outs Above Average going to his left, +4 Outs Above Average going to his right, +7 Outs Above Average coming in and +1 Out Above Average going back. And he was strong against everybody -- Báez was +13 Outs Above Average making plays on right-handed hitters, +6 Outs Above Average against lefties.

At shortstop, Báez's skill shone. He was +8 Outs Above Average on the middle 50% of plays -- the ones with an estimated success rate between 25-75%, not so extremely difficult that they're a dice roll, not so easy that everyone will make them. Báez had 34 chances in that range. His expected success rate on those plays was 55%. He actually made 78% of them.

That's basically one extra out on every four chances, on non-routine plays. That's what separates Báez from other fielders, who just can't do what he does. El Mago was a force all over the field.