Image courtesy: Ben Jedlovec, Baseball Info Solutions

Image from earlier this season shows the difference between Brett Gardner and other left fielders.Brett Gardner got robbed.

There is one statistical justification for Royals leftfielder Alex Gordon winning the American League Gold Glove award for that position -- his league-leading total in assists (20). But there's a lot more statistical justification for Gardner.

Advanced defensive metrics show that Gardner was the best of the best in the majors this season. He was one of the Yankees' best chances at a Gold Glove, but he, first baseman Mark Teixeira and second baseman Robinson Cano were denied in voting announced Tuesday night.

Brett Gardner

2011 Defensive Highlights

There are two metrics available publicly that measure defense: Defensive Runs Saved and Ultimate Zone Rating (UZR). Gardner had the highest UZR in the major leagues by a considerable margin and tied with Tigers center fielder Austin Jackson and Giants third baseman Pablo Sandoval for the most Defensive Runs Saved.

In fact, among AL left fielders, Gardner had more than twice as many Defensive Runs Saved (22) as anyone else (Rays left fielder Sam Fuld ranked second with nine). Gordon finished with four Defensive Runs Saved.

Gardner also led left fielders in "Good Fielding Plays," a stat tracked by Baseball Info Solutions (BIS), a group that reviews and categorizes video of every pitch of every game.

A Good Fielding Play is like a Web Gem nominee -- a catch on a ball that was more likely to be a hit than an out, reaching into the stands to catch a foul ball, or cutting off a ball before it reaches a fence to prevent a single becoming a double. Gardner had 33 Good Fielding Plays in 2011 (two more than Gordon), 22 of which were related to catches he made.

A search of "Brett Gardner 2011 catch" in MLB.com's video archives yields 19 different nifty plays by Gardner last season, such as the lead-preserving running catch he made in the eighth inning against the Orioles on April 24, a sliding backhand snag to take away a hit from Carl Crawford and the Red Sox and a diving catch against Twins infielder Tsuyoshi Nishioka on Aug. 19

Where Gardner is statistically strongest is in the area that is probably the toughest to fully understand -- turning batted balls into outs. He makes catches that other left fielders don’t make. This is hard to fully evaluate using basic stats because if a fielder just misses a ball, he isn't charged with an error. The batter is credited with a hit.

What BIS does to evaluate defense is that its game-watchers chart every batted ball, categorizing it as a fly ball, a line drive, a "fliner" (between a fly ball and line drive) or a ground ball. They then compute the hang time if it's a fly ball, and determine via video review where the ball landed.

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This allows them to create the equivalent of an approximate batting average for a ball hit to every spot on the field. Using this data, they create a plus-minus rating, calculating how many more plays a player made at his position and how many more bases he saved (ie: some of the plays would have been doubles and triples), than the average player at his position.

Gardner's plus-minus ratings were +21/+31 (21 plays above average, 31 bases saved above average), both the best among left fielders. The +31 is the second-highest total for any left fielder since BIS began tracking the stat in 2003.

That's one reason why Gardner won a "Fielding Bible Award," an honor given by BIS based on a panel vote that rates the best defensive players.

By comparison, Gordon was among the worst left fielders in this regard. His ratings were -8/-14 (eight plays below average, 14 bases below average).

Gordon's strength was in the deterrent value of his arm. But by advanced stat methods used by BIS, Gardner was rated as having the second-best arm rating for left fielders, a distant second to Gordon, but second in the entire major leagues nonetheless.

There are many factors that come into play regarding a left fielder’s ability to have a high plus-minus rating, including but not limited to where he is positioned, where his teammates are positioned, his speed, his ability to run good routes, his fundamental defensive skills and how frequently balls are hit to the outfield among them.

Baseball-Reference.com charts hit location data in simpler terms. They tally the Yankees as having allowed 290 base hits to left field this season, fewest in the majors, 30 fewer than the team with the second-fewest (Phillies, 320). Yankees left fielders also recorded 339 outs, eighth-most in the majors.

Gardner played around 80 percent of the Yankees innings in left field. You’d like to think that some of the credit belonged to him. But apparently it wasn’t enough to merit a Gold Glove.