Baseball's best-fielding double-play combo? The answer is a surprise

Which team has the best-fielding keystone combination in baseball? The answer will surprise you.

Your initial reaction may be to think that this is an easy question. After all, in 2010 the Yankees' double-play combination, Derek Jeter and Robinson Cano, became just the 10th pair to win Gold Gloves in the same season, and the first since the Cardinals' Edgar Renteria and Fernando Vina did so in 2002. That would seem to give New York's duo a stranglehold on the honor of best-fielding middle infield in the game.

That might have been the case a generation ago, but the Gold Glove Awards are no longer the last word -- or even the next-to-last word -- in evaluating defense. As more and better ways of measuring a fielder's effectiveness have come online, the opinions of coaches and managers have carried less weight. While Gold Glove Awards are an excellent measure of a player's defensive reputation, in the 21st century, reputation and performance are two very different things, and players should be judged on the latter. To measure defensive performance, we use numbers such as Ultimate Zone Rating (UZR, developed by Mitchel Lichtman and available at Fangraphs) and plus-minus (+/-, developed by John Dewan and available to subscribers at Bill James Online). These numbers, which evaluate defense the same way we evaluate offense -- measuring performance in the context of opportunity -- indicate better than any poll whether a defender is preventing runs for his team.

When you look at these state-of-the-art numbers, you find that the Yankees' duo is nothing special. Jeter rates as below average in both systems, costing the Yankees five to 10 runs last season with his declining range. There's less of a consensus on Cano, who shows up as average by UZR and a bit above -- but not in the AL's top five -- by +/-. Together, the two are nowhere near the best combination in the league.

Unlike the Yankees' duo, the best middle infield in baseball wiles away in obscurity for a team that hasn't reached the postseason in four years, that rarely appears on Sunday Night Baseball or the Fox Game of the Week, that is better known for its failures over the last decade than its successes. The A's Mark Ellis and Cliff Pennington are the top middle infield duo in baseball. Pennington, in his rookie season, saved about 10 runs with his glove, second in the AL only to Alexei Ramirez. He was seventh overall in MLB by +/-. Ellis has long been an underrated defender, and once again healthy last year, he posted a +9.9 UZR and +8 +/-. Oakland's strong defense was a key element in Trevor Cahill's surprising season, and represents a big part of the reason why the A's are the Rangers' primary AL West challengers in 2011.

The only DP combination with a potential claim to the A's title is the one in Philadelphia. Chase Utley (+10.3 UZR, +16 +/-) and Jimmy Rollins (+6.9 UZR, +5 +/-) were actually ahead of the A's pair by +/- last season. The relative youth of Oakland's duo (Utley is a year younger than Ellis, but Pennington is six years younger than Rollins) is why I place them ahead of the two Phillies, but you can make a case that the Phillies duo's longer track record gives them the edge. Like Ellis, Utley has been the best defensive second baseman in his league for a while without ever winning a Gold Glove.

At the other end of the spectrum, you find a couple of teams that figure to be terribly hurt by their up-the-middle defense. The rebuilding Pirates paired failed prospect Ronny Cedeno with converted third baseman Neil Walker a year ago, with disastrous results. It will be interesting to see if Rule 5 selection Josh Rodriguez can push Cedeno aside, while we wait for the team to shuffle Walker back to third and Pedro Alvarez to his eventual position of first base. The Pirates will have to upgrade their internal defense as part of their path back to relevance.

More costly in the short term is the Cardinals' double-play combination. A year ago, converted outfielder Skip Schumaker was one of the worst second basemen in baseball, costing the team more than one win just with his poor defense. Now, the Cardinals have brought in below-average defender Ryan Theriot to pair with Schumaker, trading away the player who had the best defensive season of any shortstop in the game in 2010, Brendan Ryan, to do so. A team that leans on ground ball pitchers such as Chris Carpenter, Jaime Garcia and Jake Westbrook may find itself ruing the absence of a key defensive cog, especially if Schumaker continues to display poor range in his third season as a second baseman.

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