Not too long ago, we took a look at the Jays' pitchers for 2009, using tRA and tRA+.  Now let's look at a related factor in preventing runs, defense.  Defense in baseball is a fascinating thing - while it is clearly very important in determining a players' value and for a team in preventing runs, particularly at certain positions, there is no perfect way to measure it.  We'll use a number of stats in this analysis of what can be expected of the Jays' defense in 2009. 

In 2008, the Jays finished 2nd in the American League (to Tampa) in defensive efficiency, a stat that measures the skill of a team's defense in converting batted balls into outs.  As one might imagine, this is an extremely important metric in that the sample size of batted balls over the course of a year is large enough that it is useful and it appropriately weighs the positions in which defense is most important (since those positions have to play more balls).  As you can see, the quality of the Jays' defensive play was a big factor in the ability of Jays' pitchers to prevent runs.

That said, there is every reason to believe that the 2009 Jays will be even better. 

Catcher:

Starting behind the plate, Rod Barajas was an above-average catcher defensively, as measured by things like passed balls and runners attempting to steal (12 runs above average per Baseball Prospectus, 6 runs above replacement per SBN sister Beyond the Boxscore.  Gregg Zaun, who caught in 79 games as compared to Barajas' 98, was not.  Although Barajas is a year older, starting the year with Big Rod (also his porn-star name) behind the dish should more than compensate for that.  How we could see a decline: if Barajas gets hurt and Michael Barrett becomes the everyday catcher, he's never been known for his receiving prowess. 

First Base:

At first base, Lyle Overbay had yet another excellent year in the field in 2008.  Fielding Bible's +/- had him at +12 in 2008, and has him as the third-bast fielding first baseman in either league over the past 3 years.  Beyond the Boxscore's fielding runs above average, UZR, and Baseball Prospectus all agree that Overbay is an excellent fielding first baseman.  And none of these fielding systems account for one of Lyle's greatest defensive skills, scooping errant throws out of the dirt.  Although Lyle is a year older, good-fielding first basemen tend to age well defensively.  There's absolutely no reason to believe he'll be any less than excellent again in 2009.  How we could see a decline:  If Overbay doesn't start hitting lefties again, we could see a lot of Kevin Millar and/or Jose Bautista at first base against them.  Millar hasn't been a good fielder at first since his Ruddy Hose days, and Bautista looked awful at first in limited action last year. 

Second Base: 

Moving over to second base, there's no doubt that Joe Inglett did an excellent job filling in last year when Aaron Hill went down to a concussion.  Beyond the Box Score ranked him as the 15th most valuable second baseman in the game in 2009, which is quite good for an injury-fill in who didn't even get to play a full season.  All the metrics (other than UZR, which for some reason, didn't like Joe at all) had Inglett as slightly above-average for a second baseman in the field, with Plus/Minus liking him best at +7.  That said, Aaron Hill is in a different class defensively,  The Fielding Bible ranked him best in all of baseball in 2007, his last full season, and 3rd best in all of baseball over the past 3 years (and that's including his injury-marred 2008) and UZR has always been a huge fan of his as well.  If Hill is on the field, this is a substantial defensive improvement at an important position.  How we could see a decline:  I don't know, a string of injuries whereby Russ Adams is manning second? 

Third Base:

At the hot corner, Scott Rolen enjoyed another excellent season with the glove in 2008 in the 115 games he was able to play.  Only Adrian Beltre played a better third base than Rolen, according to Beyond the Boxscore, and +/- consistently ranks him as one of the best in the game, as does UZR.  That said, Marco Scutaro did a lot of the filling-in for Rolen last season, and Marco was, if anything, even better at third base than was Rolen.  The stats suggest that Scutaro has always been a quality-fielding third baseman.  So while Rolen staying on the field would certainly increase the Jays' offensive productivity from the hot corner, it likely wouldn't make much of a difference fielding-wise.  How we could see a decline:  If Rolen isn't able to play, we may see a lot of Jose Bautista at third base.  Bautista is not a good fielder at third. 

Shortstop:

Moving on to the important six hole, Marco Scutaro played about 500 innings there in 2008, and the fielding stats agree that he did an excellent job.  BtB had him at over 2 wins over average in the field (21 runs), while the Fielding Bible put him at +12 in 2008.  UZR also rated Scutaro incredibly highly, 19.7/150 games, which agreed with BtB that he was worth about 2 full wins in the field above replacement.  Now, Scutaro had never really been well-regarded as a defensive shortstop before, so those numbers appear suspect, but when all the fielding stats agree that is usually pretty good evidence, at least for that year.  Scutaro essentially split playing time at SS three ways with John McDonald and David Eckstein, and it looks like Mac will be back and Eckstein won't.  If Scutaro gets more playing time and plays like he did last year, defense at short would improve, since Eckstein was lousy with the glove in 2008 (exactly as far below average as Scutaro was above) and Mac was average at best (at least, if you look at +/-, FRAA, and UZR and not announcer comments).  If Mac plays like he did in 2007 defensively, that'd also be a boost.  How we could see a decline:  If Scutaro gets hurt or proves last season was a total flash-in-the-pan.  However, even if he is merely average with the glove but gets more of the playing time, things will stay the same from last season overall. 

Centre Field:

In the outfield, Vernon Wells had a terrible 2008 with the glove by any metric.  Or, to look at it another way, +/- though Wells was even better than gold-glove winner Nate McLouth (McLouth was rated by FB, by far, as the worst centre fielder in baseball, Wells was third-worst).  This really hurt Wells' value.  What's intersting, though, is Wells was never a bad centre-fielder defensively before.  On the contrary, UZR thought Wells put together many solid seasons in a row before an average 2007 that was marred by injury.  Now, it's possible that Wells has declined and is now a well-below average centrefielder.  But it's also possible that either it was a 1-year blip or that Wells' hamstring injury slowed him down in the field.  If Wells is recovered, one could see him bouncing back to at least average defensive levels.  During the 60 or so games Wells missed, Alexis Rios got the bulk of the time in centre and he was outstanding.  Fielding Bible had him at +11 and UZR thinks he is the best defensive outfielder, give or take, in all of baseball.  If Wells plays more, that means less of Rios' outstanding work, unless Cito heeds our advice and starts flipping the two from time to time, or giving Wells some DH work, which would cut into the overall gain in defense one would expect.  How we could see a decline:  If Wells is healthy enough to stay in centrefield but continues the poor play we saw there in 2008.

Right Field:

Alex Rios played most of the Jays' right field innings and as we discussed, he was spectacular by any metric.  When Rios was in centre, Brad Wilkerson saw most of the time in right and was quite decent in the field.  Expect more excellence from Rios in 2009.  How we could see a decline:  Rios has to man centre and Travis Snider doesn't show well in right field.  That's unlikely to be a significant decline at all, though. 

Left Field:

In left, Adam Lind, Kevin Mench, Shannon Stewart, Brad Wilkerson, Joe Inglett, and Travis Snider all played double-digit games, with Lind getting the most work (71 games).  Lind was a bad outfielder in 2008 after a surprisingly excellent showing in let in 2007.  The others were all ok at a not-particularly-important defensive position.  Travis Snider appears set to take most of the innings in leftfield in 2009 and while he hasn't looked great there this spring, one would think he would have to be better than Lind since the Jays are set to DH Lind most of the time and put Snider in left.  I also think Lind should improve in the field, at least from 2008, so we're likely to see an overall improvement, if a small one.  How we could see a decline:  Jose Bautista has looked awful in the outfield in limited time this spring.  Snider hasn't exactly looked good there either. 

So, there you have it.  At no position are we likely to see a defensive decline from 2008's excellent heights, and we are set for at least one big improvement at 2nd base.  Other positions where the Jays could very likely improve are centrefield, shortstop, and catcher.  These are, by far, the four most important defensive positions on the diamond, meaning the Jays are very likely to be even better defensively in 2009 than they were in 2008.  At the very least, their excellent defense from last year should continue. 

Thanks to Bad Religion for our ridiculously appropriate title.