The 2017 MLB season has featured some incredible offensive storylines, with perhaps none as compelling as the power breakouts of rookie sensations Aaron Judge and Cody Bellinger. As the calendar flips to July and Judge, Bellinger and other great hitters receive their due attention in the All-Star festivities, Baseball Info Solutions (BIS) wants to put some of that spotlight on the best defensive performers of the first half. To do so, I've put together my list of defensive all-stars based on a combination of defensive runs saved (DRS) -- BIS's comprehensive estimate of player defensive value on a scale of runs that he saved or cost his team -- its component statistics and my own opinions as a detailed follower of the sport. I've selected just one player per position, so the following players are truly the best of the best glove men.
First base: Brandon Belt
San Francisco Giants | 8 DRS
So far this season, the Giants have been the second-worst defensive team in baseball. That's a far cry from their third-place finish in DRS from a year ago and one of the biggest reasons why they've tumbled to the second-worst record this season at 31-51. But Brandon Belt's inclusion among the defensive all-stars is not a case of every team needing a representative. Thanks to his exceptional range, Belt leads all first basemen in DRS. If he maintains the pace he is on, he has a chance of earning the odd distinction of saving the most runs of any player on a bottom-two defensive team this decade. Ian Kinsler did that for the 2014 Tigers with 20 runs saved on a team that had minus-61 DRS overall, and no one else on a qualifying team has eclipsed 10 DRS.
Second base: DJ LeMahieu
Colorado Rockies | 8 DRS
During his peak performance on defense from 2013 to 2014, DJ LeMahieu was in the mix for being the best defensive second baseman in baseball, but he was always just out of reach of more famous players like Dustin Pedroia and Kinsler. This season, that could change. LeMahieu is having a defensive renaissance, currently leading all second basemen in DRS. In addition, his team is also on track for its first playoff berth since 2009, which should draw a few more eyeballs on LaMahieu's performance.
LeMahieu's best attribute is his sure-handedness, having saved runs making good fielding plays (GFPs) and avoiding defensive misplays and errors (DMEs) in six of his seven seasons. He also excels making plays up the middle, where he tends to make strong and accurate throws even when he's on the ground or his momentum is taking him away from first base. He has saved six plays above average on balls hit up the middle this season.
Third base: Nolan Arenado
Colorado Rockies | 15 DRS
Colorado's second representative on our defensive All-Star team is probably its least surprising member. Arenado is more firmly entrenched as the game's best defensive third baseman than any other player is at his position. He is also really fun to watch, especially if you like web gems. After a pair of second-place finishes on the good fielding plays leaderboard in his rookie and sophomore seasons -- which he accomplished in only 130 and 111 games played, respectively -- he has rattled off three consecutive seasons with the most GFPs among third basemen. Those GFPs tend to be unexpected outs on ground balls, many of which are on lunges and dives.
Shortstop: Addison Russell
Chicago Cubs | 12 DRS
The Cubs may have underperformed this season as far as wins and losses, but they remain a great defensive team with 35 runs saved. The player most responsible for that continued team success is Russell at short. He does his best defensive work in the third base-shortstop hole, where he has saved 13 plays more than an average shortstop this year. Those plays showcase Russell's exceptional athleticism and arm strength, which may remind you of another player whose similar skill set routinely catapulted him to the top of the DRS standings at the position over the past few years: Andrelton Simmons.
Left field: Alex Gordon
Kansas City Royals | 9 DRS
Even when the Royals outfield was playing at peak performance in 2013-15, Gordon never covered the same ground as his teammates Lorenzo Cain and Jarrod Dyson. This season, Gordon has saved his team five runs with his range in left field, which puts him on his typical good-but-not-great pace for the season. But the former third baseman sets himself apart from others at his position with his incredible throwing arm. Gordon has thrown out four runners this season without a relay man, which we call outfield kills. That total would no doubt be higher if not for Gordon's reputation, which deters challenges. Baserunners have only taken an extra base against Gordon 27.8 percent of the time this season -- the lowest rate at the position among regulars -- because everyone has learned how much of a threat his throwing arm is.
Center field: Byron Buxton
Minnesota Twins | 15 DRS
The Twins have had the opposite season of the Giants. After finishing tied for the second-worst DRS total of minus-50 in 2016, the Twins have improved by 76 runs this season and are making a real race of the AL Central with last year's pennant winner, the Indians. Buxton has epitomized the team's roster rebuild with added youth and athleticism. He's a defensive wizard in center field and currently leads the position with 15 runs saved, 13 of which have resulted from his range. He is also responsible for what will probably end up being the best defensive play of the season when he crashed into the wall in right-center field to rob Carlos Santana of extra bases in the sixth inning on May 14, evoking memories of Ken Griffey Jr. in his prime. Overall, Buxton is his most dangerous on shallow balls, where he has saved 10 plays above average this season and 17 so far in his short career.
Right field: Mookie Betts
Boston Red Sox | 17 DRS
Betts led all players at all positions in DRS in 2016, and, incredibly, he's on pace to do the same again this season. In fact, Betts already has more than half of his 32 runs saved total from last year in less than half the games played. By pace, that suggests that he could exceed last season's remarkable total, but some of his underlying totals indicate he may end up falling a bit short. He is on pace for fewer outfield kills and for more defensive misplays and errors than a year ago. He has overcome those marginal setbacks by robbing a pair of home runs -- one against Nelson Cruz on May 27 and another against Chris Carter on June 7 -- which netted him 3.2 runs saved, but that cannot reasonably be expected to continue over the second half. In the end, the Red Sox may have to "settle" for Betts saving them 25-30 runs this season.
Pitcher: Tyler Chatwood
Colorado Rockies | 6 DRS
There are several pitchers bunched together at the top of the DRS leaderboard, including three-time reigning Fielding Bible Award winner Dallas Keuchel with five runs saved. Rather than select those options, many of which are established names like Keuchel, I think Chatwood deserves recognition for the defensive season he's putting together. Chatwood separates himself from pitchers like Keuchel and Mike Leake -- who have saved the bulk of their runs this season on batted balls -- by contributing on all aspects of pitcher defense we measure: ranging to make plays, defending bunts, making good plays and avoiding misplays, and preventing the opposing running game. Chatwood has been especially good on that last point, having allowed just four successful stolen bases against five caught-stealing attempts and two pickoffs. He's one of just 11 right-handed pitchers with two or more pickoffs this season.
Catcher: Yasmani Grandal
Los Angeles Dodgers | 13 DRS
Since his debut in 2012, Grandal has been on the short list for the best defensive catcher in baseball, which he has accomplished almost entirely on the strength of his framing ability. Among active catchers, Grandal has gotten the most extra strike calls per 100 called pitches in that time frame, and it's not particularly close:
That trend has continued this season as Grandal has earned 50 extra strike calls, and he has also added a new dimension to his defensive game. After costing his teams eight runs with his stolen-base defense over the previous four seasons, Grandal has saved the Dodgers five runs on stolen bases this year. He has already thrown out 12 runners attempting to steal, which is top-five in baseball this season and fast approaching his career high of 19 from 2015. Grandal's improvements coupled with the lack of exceptional seasons from other established glove-first catchers makes his selection as the last defensive All-Star an easy one to make.
Scott Spratt is a research analyst for Baseball Info Solutions. You can follow him on Twitter (@Scott_Spratt).