Think back to this off-season. The Rangers had accumulated what they thought was a fairly deep bullpen and saw fit to trade the presumed setup man, Frank Francisco for a catcher with questionable defensive chops but a penchant for launching deep bombs and taking walks.
The thing is, Mike Napoli was considered merely a good hitter at that point of his career. When people talked about Napoli's offensive game, their analysis was filled with caveats.
"Oh, he hits well... for a catcher."
"He can platoon against lefties! A new Francouer, everybody!."
It turns out Mike Napoli's a lot better than anyone gave him credit for. If he had enough at-bats to qualify, his .973 OPS would rank 3rd in all of baseball. His .418 wOBA (Weighted on Base Average, a stat which presents an overall offensive picture, even taking into account things like base-running) would put him in a third place tie with Joey Votto on the leaderboards.
2011 has spawned career highs in almost every aspect of his game. But what's causing this kind of surge? Let's take a deeper look.
Napoli spent the first five years of his career with the Angels. Los Angeles' ballpark is a certified cavern which suppresses offense, especially home runs. Napoli has a career line of .248/.343/.493 in the Angels' stadium, poor considering his career averages and the natural advantage of playing at home. For reference's sake, Napoli's a .286/.388/.592 hitter in Arlington.
In fairness, though, those numbers are skewed by his success this year. So let's move on from park factors and take a look at what's fueled this year's dominant play.
Napoli's what's classically known as a "Three True Outcomes" hitter. He hits a lot of home runs, elicits more than his fair share of walks -- and strikes out in bunches. Over his career, he's posted an 11.3% walk rate and a 24.7% strikeout rate. The former is good. The second is quite poor.
This year: 12.4% walks, 19.4% strikeouts. It may not seem huge, but that's a big year-to-year difference.
One big cause for all this: Napoli's seemingly become better at hitting the ball. He's making contact with 65% of balls thrown outside the zone -- a 10% gain over his career averages. This doesn't necessarily lead to weakly hit balls -- in many cases, it shows he's able to spoil a tough pitch and extend the at-bat. It's likely the reason for the lower strikeout rate. More proof in the pudding: His overall swinging strike rate has fallen from 11.9% to 10.8%, a significant cut. If pitchers can't make a hitter whiff, it's much harder for them to strike him out - they need to locate precise, deceptive pitches on the corners of the zone.
Napoli hits into a lot of fly-balls, has an average line drive rate and pops up a little more than average. His 2011 batted balls fall pretty closely in line with the career norms, beside a slightly lower pop-up rate. His batting average on balls in play remains a little lower than usual, meaning there's actually reason to believe Napoli's actually been a little unlucky so far.
Finally, the most important factor of the batted-ball equation: How much power is Napoli showing?
A good way to figure that out is dividing home runs by fly balls. Keep in mind this is the number most affected by the move from California to Texas; fly balls are more prone to clear the fences in Arlington than they are in Los Angeles. Napoli's gone yard on 22.3% of his fly balls this year. Over his career, he's jogged the bases on only 18.8% (Still a huge number.)
More fun with numbers: Napoli's home run rate would rank fourth in all of baseball if he qualified. It would outstrip the raw power numbers of Curtis Granderson, Matt Kemp, Prince Fielder and Ryan Howard.
It's clear Napoli's improved multiple aspects of his game. But there's no sure explanation for what caused the leap in Napoli's contact ability. One possible explanation, which would also cover why he's looked a lot better behind the plate than he ever did with the Angels: He's simply happier and more comfortable than he was in Los Angeles.
Angels manager Mike Scioscia was never a big fan, usually playing Jeff Mathis over Napoli. Mathis is a strong contender in any competition aimed at finding the worst regular player in MLB. Some context: Mathis' OPS is 114 points lower than Mike Napoli's Slugging Percentage.
Additionally, Napoli has nabbed 9 of 21 potential base-stealers this season. Jeff Mathis has caught 16.... of 59.
Getting out from under a manager who was never comfortable with him seems to have done wonders for Napoli. Credit should also be given to the Rangers' front office, who identified a perfect fit for the team's ballpark, offense and defensive depth and dealt a seemingly redundant (and currently struggling) player for him. Napoli won't keep this up; he's not one of the five best hitters in baseball. But he's a legitimate star, and should be a huge resource for the Rangers until his contract expires in 2012. At that point, the money he's offered could get scary.