Boston's Best Tools: Best Defender

Before the 2010 season began, defense was the buzz word around town. The front office talked about the need to improve the team’s fielding and backed that talk up by signing defensive wizards Adrian Beltre and Mike Cameron. Unfortunately, the plan did not come together. Beltre was masterful at the hot corner, but Cameron and projected left fielder Jacoby Ellsbury were both hurt the majority of the season. Their replacements were woeful defensively and to make matters worse the Red Sox lost slick fielding second baseman Dustin Pedroia and first baseman Kevin Youkilis as well. All told, the 2010 Red Sox were a poor defensive team, rating 56 runs below average by the Defensive Runs Saved metric (DRS) and -15 runs by Ultimate Zone Rating (UZR). 

As 2011 rolls around, the Red Sox are once again hoping for improved defense. They have added the premiere left fielder in the game in Carl Crawford and shuffled the infield to accommodate newly acquired first baseman, Adrian Gonzalez. Their top fielder last season, Adrian Beltre, is gone, replaced by Youkilis, who shifts back to his original position. With an excellent starting rotation in place and a revamped bullpen, better glove work will be a key factor in run prevention. Whose glove will have the biggest impact though?










Adrian Gonzalez









Carl Crawford









Dustin Pedroia









J.D. Drew









Kevin Youkilis










Defensive statistics are full of problems. It is simply the nature of the beast. Among the baseball stats community two main approaches have developed for analyzing defense. The first system, represented by Sean Smith’s Total Zone system, uses play-by-play data to estimate the number of plays above or below the average from the historical norms for each hitter and pitcher. The second system, represented by Mitchel Lichtman’s Ultimate Zone Rating, uses data from Baseball Info Solutions detailing the type of hit and the area in which it was fielded to estimate the number of plays above or below average.. For our purposes, we will look at several systems and try to reach some understanding between them.

Shown above, I have two location data based systems (DRS and UZR), the modified version of Total Zone’s system (TZL) and the Fans Scouting Report data (FSR). All systems express the fielder's impact in runs, not plays made. Each one has its own advantages and disadvantages.

The main problem with all defensive metric is the high levels of variation. For this reason, I have limited this conversation to players with over 1000 innings at each position. This has left out Jed Lowrie’s excellent work at shortstop (UZR credits him with 7+ runs saved in just over 700 innings) and Jacoby Ellsbury’s time in left (where UZR has him at 10.5 runs saved in 392 innings) Both of these players deserve mention, but the uncertainty around those numbers is too great to ignore.


Regardless, the answer is loud and clear. Carl Crawford is the best defensive left fielder in the game and possibly one of the greatest of all time. He has a substantial advantage in runs saved over Pedey, who gets the silver medal. The others aren’t even close. Crawford plays the easiest outfield position though and the average is affected by the many lead-footed sluggers hiding out in left field. By contrast, Pedroia is a top defensive player at a premium position and that is an important distinction. In 73 fewer innings, Pedroia made over 150 more plays. That is significant, but it doesn’t make up for such a huge gap.

The other three players here are all very good defenders. Adrian Gonzalez struggled last season, but has been very good with the glove at first. Two of the systems even prefer him to Youkilis, who is the best defensive first baseman in the league. The loss of Beltre will certainly mean a downgrade at third base, as Beltre is unrivaled there. Shifting Youk won’t have a huge impact at first base though, given how good Gonzalez is. Youk has been good at third in his limited time there and should be at least average, if not better, over a full season.

The outfield could very well be incredible next year. It would be hard for it much worse than 2010. J.D. Drew was the only outfielder to post a positive UZR last season. He will now team up with Crawford, Ellsbury and Cameron to create what should be a very good outfield. Beyond Red Sox fans, Drew doesn’t get much credit for his play in right. He doesn’t have the cannon of an arm associated with great right fielders, but he gets to many extra fly balls and that is really more important. If he splits time with Cameron, the platoon should be excellent defensively and boast the offensive production as well.

The 2011 Red Sox have added offensive fire power without sacrificing defense. In fact, they may be a very good defensive team. The hype surrounding their emphasis on fielding might have died down some, but Theo and Co. haven’t given up on finding elite defenders. If the 2011 Red Sox field well, it will be Lester, Buchholz, Beckett and the rest of the staff that benefit the most.

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