Or does it?

No, your league isn’t likely to add UZR/150 or Total Zone as a category next season. But if you’re playing in an AL or NL only league – or even a mixed league – defense could play a huge impact on several players production.

Let’s start with an obvious example. Mike Napoli. The Angels catcher could be a great fantasy asset. He has a tremendous amount of power, hits in the middle of one of the better lineups in baseball, and probably wont destroy your batting average. There’s just one problem. He’s failed to reach 400 at bats during any season in the big leagues. He hasn’t bee the healthiest guy out there, but he did spend most of last season on the active roster. So why can’t he get into the lineup if he’s such a good hitter?

A quick look at Driveline Mechanics 2009 defensive runs above average shows us why. Napoli was just about the worst defensive catcher in the Major Leagues last season, costing his team almost 10 runs behind the plate, despite catching fewer than 100 games. While Joe Mathis isn’t exactly a stud by these metrics, he’s certainly better than Napoli, and Mike Scioscia considers him one of the better defenders in the league.

But that’s pretty obvious, right? Most fantasy players know this. Let’s look at a less obvious example.

I was listening to the Fantasy Baseball Roundtable Tuesday night, and they were discussing the Oakland A’s outfield situation. This is a huge deal in most formats – guys like Rajai Davis, Coco Crisp, and Michael Taylor could be major fantasy assets if given playing time, and are especially valuable in mixed leagues.

Totally aweseome outfielder.

One guy who isn’t exactly a fantasy stud is Ryan Sweeney. While Sweeney is a career .284 hitter – and hit over .290 last season – he hasn’t developed much power and isn’t going to steal many bases. You could do worse in AL only leagues, but we’d certainly rather see a guy like Coco Crisp – who could steal 20-30 bags – get the playing time. The question was, why is Ryan Sweeney getting 500 plate appearances? He hits for a solid average, but guys with sub-.400 career slugging percentages don’t usually start in corner outfield spots. What do they see in Ryan Sweeney?

One word. Defense. Last year, Ryan Sweeney was worth 24 runs defensively over the average player between CF and RF. That’s about equal to the offensive contributions of Raul Ibanez, Robinson Cano, or Ichiro Suzuki. He also has a bat right around league average. Now, if I told you that you could have Robinson Cano’s bat, and league average defense (that’s basically what Cano gives you, and I’m being kind) wouldn’t you take that? According to FanGraphs, Sweeney was a 4 win player last year in only part time play. Those guys are incredibly rare, and he was worth over $18 million dollars. Billy Beane isn’t going to give that guys job away to a scrub named after a brand of cereal.

This is where defense really matters in fantasy baseball. You’re average fantasy owner will look at the Oakland A’s outfield situation, see Ryan Sweeney’s mediocre numbers, and decide he wont keep his job going forward. But add in a 20+ UZR, and he goes from a 4th outfielder to a 4 win stud who is very unlikely to lose his job.

A couple more examples of this can be found in Michael Young and Johnny Peralta, who both had to move to 3B (a less scarce position) because of their poor defense. Or even Nyjer Morgan, who was able to gain consistent playing time because of his glove.

While this might not help you in too many situations (Derek Jeter isn’t going to lose his job to Ramiro Pena, no matter how bad his defense is) it’s just another piece of information that can help you when looking at position battles and bench players who may get a chance to play everyday. More useful in AL and NL only leagues, but can have an impact in any format, as the A’s outfield situation shows.

Let’s first look at what we have in Roy Halladay. Yes, he’s 32, but his skill set remains completely intact, with his K rate, K/BB rate, and velocity all at or around career highs. He’s pitched 220 or more innings the last four seasons, putting his injury-prone label behind him. Furthermore, his last two seasons, he has reached levels that he had not reached since his mid-20s, when he won a Cy Young.

When Roy found out what the Angels were offering for him, and realized he would never get out of Toronto...

So what did the Angels offer? Joe Saunders, Peter Bourjos, and Erick Aybar. Saunders has a career FIP of 4.63. Last year, his worst season to date, he had a FIP well over 5 and a K/BB rate around 1.6. He is about league average, if not slightly above league average, from a GB rate point of view, but when you’re striking out less than 5 batters per nine innings, and walking more than 3, you suck. Always. Pretty much no exceptions that I can think of over the past couple of decades. After that, it gets a bit better. Erick Aybar was actually fairly good last season. No, he isn’t much with the bat, although he did hit .312 with a .339 wOBA in 2009, a huge improvement over his previous seasons. Most of his value comes from good defense (career UZR/150 around 7). But that’s what we have here. He’s 25, so he could get better, but he’s always going to be a light hitting defensive shortstop. Bourjos is yet another solid MLB player at best. He’s a borderline top-100 prospect with good speed and defensive skills, but a poor stick and no power. So we are looking at one horrible player and two solid ones for Roy Halladay?

Even worse, people have been calling this a “big package” for one of the best pitchers in baseball, and the best deal out there. It’s just absurd.  The Angels have even hinted at the possibility of other players coming back in a deal, and the rumor was that Aybar was borderline untouchable earlier this off-season. What am I missing?

Joe Sauders had a 3.41 ERA in 2008. He also pitched a few good games down the stretch last year. This automatically makes him a “good young pitcher.” We don’t mention the fact that he had a 4.36 FIP in 2008, and a .267 BABIP, as well as the fact that his control completely fell apart last year. And Aybar hit .312, so he must be a good hitter right? And he has a great defensive reputation, right? He’s basically Elvis Andrus, except 25 years old, with much less speed and upside. He’s a solid player to have around, but people need to realize he’s nothing more than a light hitting, slightly above average starting Major League SS. And Bourjos… well I have no idea where that hype is coming from. He’s a solid young prospect, who could be a solid MLB player. But he’s not the kind of guy you build a package around for an ace.

People need to stop acting like this is a reasonable deal, just because the Blue Jays last GM (who, if you didn’t notice, wasn’t very smart) offered a similar package and had it turned down (allegedly). It was a stupid move by both teams, and I doubt the Blue Jays pull the trigger on this deal. If they do, it just signals that they are even more of a backwards thinking, poorly managed organization than they have been the past few seasons, which is saying something.

The Blue Jays can make the smart move, which is take offers from the top teams (Yanks, Angels, Phillies, and Red Sox), try and include the Mets (seriously, they’re farm system has some very nice players, especially compared to the crap they’d be getting from LA), and if they don’t get anything, offer him arbitration and take the draft picks. Or they could do the stupid thing and trade him for a bunch of role players. We all know how that worked out in Minnesota with Santana.

Just to go over a couple of the more reasonable rumored deals out there:

Another rumored deal out their involves the Phillies. This one isn’t so bad. The Phillies would send JA Happ and one of Michael Taylor/Domonic Brown for Halladay. Given the choice of Brown or Taylor, I take Taylor. Baseball America ranks Brown the top prospect in that system, and I know he is very talented, but he needs to develop more power to be a truly elite prospect, and I’m not sure it ever will. Taylor on the other hand is the real deal. He can hit for average, and has 30-30 upside at the big league level. He’s a pretty solid defender with a good arm and good speed.  Fantasy owners should remember this guy. As far as Happ, I’m not sold on him. He’s a solid mid rotation starter, but he doesn’t have any skill that sticks out. He’s pretty average across the board, and given his age (27) and average stuff, I think it’s safe to call him pretty, well, average. I know he won rookie of the year but his ERA will go up quite a bit next year. He could be solid but he wont be special. If I’m Torono, I ask the Phillies for Drabek and Taylor, and although that might be a bit much, they could end up going for it. If not, I’d still probably consider this deal, as it’s a lot better than what you’re getting from LA, and you may not be able to pull a prospect like Taylor out of the draft. If this is the best you’re getting, and it’s on the table as is, I’d definitely consider it.

We don’t know what they could get from New York at the moment, but the package I’m hearing is Hughes/Joba, Montero, and Melky, which at least in my opinion, blows the other two out of the water. A lesser package based on one of Hughes, Joba, or Montero is possible, and would still be worth considering.