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With a lanky, 6-foot-7 frame and a cross-fire delivery that baffles hitters trying to pick up the ball, Jered Weaver exudes deception. But can Weaver, coming off a 20-win season, keep tricking batters as he enters his thirties and becomes one of the game's softest tossers? Fangraphs' Paul Swydan isn't so sure (ESPN Insider subscription required):

"Over the past couple of years his velocity -- as well as his strikeout and swinging-strike rates -- has declined...With his 20s behind him, Weaver is unlikely to see these trends suddenly reverse themselves, and he will become even more reliant on his control and defense."

Weaver struck out a career-best 25.7% of batters faced in 2010. Since then, his punchout rate his nosedived to 21.4% in 2011 and 19.2% this past season. On a related note, Weaver's fastball velocity has declined three years running: 89.9 MPH in '10, 89.1 MPH in '11, and just 87.7 MPH in 2012.

Weaver's fastball beat out just R.A. Dickey's and Bronson Arroyo's in velocity among right-handed starting pitchers last year. Yet, the pitch has defied logic by remaining highly effective despite a gargantuan dip in swings and misses. Let's take a closer look at Weaver's not-so-fast fastball, and what that velocity loss could mean for him in 2013.

Here is Weaver's fastball contact rate by pitch location over the past three seasons:

Weaver's fastball miss rate by pitch location, 2010

Weaver's fastball miss rate by pitch location, 2011

Weaver's fastball miss rate by pitch location, 2012

Back in 2010, batters swung and missed at Weaver's fastball 19.6% of the time. That was seventh-highest among all qualified starters, beating out the likes of Clayton Kershaw, Max Scherzer and Justin Verlander. Weaver's fastball miss rate fell to 15.9% in 2011, and came in at a paltry 12% in 2012 -- below the 14% MLB average and in the same finesse lefties like Paul Maholm and Tommy Milone.

But while hitters are making much more contact against Weaver's fastball, they're not doing any more damage. Check out Weaver's fastball slugging percentage by location from 2010-12:

Weaver's opponent fastball slugging percentage by location, 2010

Weaver's opponent fastball slugging percentage by location, 2011

Weaver's opponent fastball slugging percentage by location, 2012

Opponents slugged .393 against Weaver's fastball during his high-strikeout 2010 campaign, about 60 points below the major league average. Weaver's opponent fastball slugging percentage actually fell to .322 in 2011, and barely budged in 2012 (.333) as he started putting up radar gun readings that wouldn't get him pulled over by highway patrol.

Weaver's success with such a slow heater is exceptionally rare. Last year, hitters slugged .513 against fastballs thrown between 87 and 88 MPH. Basically, batters morphed into Albert Pujols when a pitcher lobbed a fastball in that velocity range. Can Weaver keep getting outs with a fastball that only the Zitos and Buehrles of the world consider fast? He does have some advantages over other soft-tossers:

His fastball command has improved as the pitch has slowed. Weaver threw about 24% of his fastballs over the horizontal middle of the plate in 2010, which is the MLB average for starters. He left 23% of his fastballs over the middle in 2011, and just 21% this past year. Perhaps Weaver's fine touch can counter the extra time that hitters have to react.
Weaver has one of the game's most diverse repertoires, as he tossed his changeup (14% of pitches thrown), slider (13%), and curveball (10%) more than 10% of the time, and nearly did the same with his cutter (9%). Not many hurlers have four other options with which to occupy hitters' minds.
Weaver's home park is death to power hitters. Angels Stadium decreased run-scoring by 14 percent for both left-handed and right-handed hitters last season, according to StatCorner. Long fly balls that become souvenirs at other stadiums die at the warning track in Anaheim.
He also benefits from playing behind arguably the best defensive team in the majors. The Angels led all clubs in Defensive Efficiency in 2012, converting about 72% of balls put in play into outs (the MLB average was about 70%). As a fly ball pitcher, Weaver can't ask for better support than Mike Trout, Peter Bourjos and Josh Hamilton keeping balls out of the gaps.
Weaver will also get to take on the Houston Astros, who join the AL West in 2013. Outside of pint-sized All-Star Jose Altuve and perhaps high-strikeout sluggers Chris Carter and Justin Maxwell, the Astros's lineup looks like a mess. Baseball Prospectus' PECOTA system projects Houston's offense for the second-fewest runs scored in the AL, topping only the division rival Seattle Mariners.

Weaver's lack of zip is concerning. Most pitchers who sit in his new, low-octane velocity range get pummeled. But if ever there were a case where a guy could Houdini his way to another 20 wins, it's Jered Weaver in 2013.