Does Defense Matter in Fantasy Baseball?

Have you ever caught yourself downgrading a fantasy player because they simply aren’t that good of a “real” baseball player? I certainly have. It’s just difficult to switch from a mind set where Jose Lopez is total garbage because he can’t get on base and doesn’t play an important position, to a mind set where he’s an absolute stud because he hits for a high average and hits a lot of home runs. So a lot of the time, I do have to remind myself of the simple fact that defense doesn’t count in fantasy baseball.

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.

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.