Jason Bay's agent off base

"The only defensive statistic that I know for sure that is easily measurable is outfield assists and errors committed, and Jason is just the third outfielder in major league history to lead the league in outfield assists while not creating an error all season, the last guy being Carl Yastrzemski. It used to be that those statistics were enough. In baseball we all need a better evaluation of defensive ability but the defensive metrics we have out there are so debatable, and in most cases proprietary, that it is hard to quantify a player’s ability to play defense."
-- Joe Urbon, Jason Bay's agent

It's hard to believe Theo Epstein did anything but start chuckling when he read the salvo from Joe Urbon, the agent representing Jason Bay this offseason, in an interview with WEEI.

No one questions the way Jason Bay hits -- and if the Red Sox offered him a four- or five-year deal, they wouldn't expect the way he hits to decline much over the course of that contract.

His fielding, however, is another story.

Bay finished this season with an OPS+ of 132 -- second-best among Red Sox hitters and 12th-best in the American League, according to Baseball-Reference.com. According to FanGraphs' Wins Above Replacement statistic, however, Bay ranked fourth among Red Sox position players and 32nd in the American League.

The reason? His defense.

Among the 29 qualified outfielders in the major leagues, Bay ranked 25th in Ultimate Zone Rating (according to FanGraphs) and 23rd in The Fielding Bible's plus-minus system (according to BillJamesOnline.com). Not since 2006, in fact, has Bay recorded a plus-minus or an UZR better than 0 -- in other words, better than average.

"It’s a surprise,” Urbon told WEEI. "I think that most people who evaluate for a living, their reaction is that that is not true. All I can go by are comments by his teammates and others who have seen him play day in and day out. Obviously the only comparison we have as a Red Sox is to Manny and that’s probably not favorable to Jason, really. But the feedback I’ve gotten from evaluators is that he plays that position as well as anybody they’ve seen, and that was really from Day 1 or Week 1 coming in and playing left field at Fenway back at the trade deadline last year."

(We'll ignore the contradiction there: He implies that Manny Ramirez played left field at Fenway Park better than Bay did and then says that Bay plays that position as well as anybody.)

Here's part of the issue: Baseball is still coming around on advanced statistical measures. (Here's a Sports Illustrated story from this spring that describes the revolution as well as anyone has.) Many talent evaluators -- and, just as importantly, many players -- still believe in the idea that the player with the fewest errors is the best defensive player.

"I don’t think anybody really believes in that stuff," Red Sox second baseman Dustin Pedroia told this writer back in May. "I don’t really know how they do that. My biggest focus is, if the ball is hit to me, pick it up and throw it and get an out. You don’t need zone ratings or anything like that to tell who’s a good defensive player and who’s not. You can pretty much look out on the field and tell who can play defense and who can’t."

Bay, of course, comes out at the top of the heap in the most widely accepted statistical measures: Errors and fielding percentage. Bay finished this season with zero errors -- fewer than David Ortiz, even -- and a fielding percentage of 1.000. No player in the major leagues -- at any position -- handled as many chances as Bay without flubbing at least one.

But there's a fundamental issue with that measurement when you're evaluating outfielders: An outfielder only can be charged with an error if he gets to a ball -- and the worst outfielders aren't going to get to as many balls. Even if an outfielder almost gets to a ball but allows it to glance off his glove, he often won't be charged with an error. The only way to guarantee the official scorer will hang an error on an outfielder is if a throw gets away and allows a runner to move up a base.

Jason Bay can throw. Jason Bay might not have the world's strongest throwing arm, but it's certainly accurate: Only Houston's Hunter Pence finished the season with more outfield assists (16) than Bay (15). Urbon certainly isn't lying when he cites statistics that show Bay's arm being both accurate and reliable.

But arm doesn't tell the whole story. It barely tells half the story. The best outfielders are the ones that chase down fly balls in every direction -- and Bay just doesn't have the ability to do that. The Fielding Bible awarded him a plus-1 on shallow fly balls and a plus-6 on medium fly balls but an abysmal minus-14 on deep fly balls.

Some uncertainty exists about how much the Green Monster hurts Bay in his statistical measures, about whether balls that hit 10 feet up on the wall count against him or not. John Dewan, the creator of the plus-minus metric, claimed in a forum on the Sons of Sam Horn message board that his system includes a park adjustment named for Ramirez, its primary beneficiary during his years with the Red Sox.

But Bay had a minus-19 in his final full season with the Pirates in 2007 and a minus-11 in 2008, a season in which he spent four months in Pittsburgh and two months in Boston. As he gets older -- he turned 31 in September -- his range inevitably will decline.

"Let’s not over-focus on the defense," Urbon told WEEI. "We used to not focus on defense at all as a free agent. Now it seems like that’s all we’re focusing on, and there has to be a reason for it."

There is: When a team is being asked to shell out $15 million a year for four or five years, the type of numbers Bay's camp presumably is throwing out there, that player had better be more than a one-dimensional threat. Bay might be a tremendous hitter and an even better guy in the clubhouse, but if he's going to have to be a designated hitter by 2011 or 2012, well, he might not be worth the type of money he wants.