What happened to Jose Altuve?

Jose Altuve is still likely the Future Second Baseman for the Houston Astros. But he is struggling this year. His current .692 OPS is the lowest it has been since the end of his rookie 2011 season (a 1x4 2012 Opening Day start notwithstanding). A year after hitting .290/.340/.399 in an All-Star (sort of by default) campaign, Altuve is hitting .286/.324/.368, and that's still with a .324 BABIP.

What the heck is happening?

He's having a harder time with fastballs.
Even though the average velocity he's seeing is almost exactly the same, his wFA (Fastball runs above average) is DOWN. In 2012, this was a 10.3. So far in 2013? -3.8. He's actually turned into a below-average fastball hitter. In fact, using these metrics from FanGraphs, Altuve is a below-average hitter on every pitch except the curve, which he has improved from a -0.4 to a 2.0.

He's swinging more, and making less contact. 
Strikeouts are up, and walks are down. He's striking out 14% of the time in 2013 - up from 11.7% in 2012. His walk rate, never impressive to begin with, is down to 5.2% from 6.3% in 2012.

Altuve is swinging at 36.3% of pitches outside the strike zone, up from 30.5% in 2012, and 46.7% of all pitches, up from 44.3% in 2012. While he made contact in 90.7% of those pitches in 2012, that has regressed to 87.2% in 2013. 5.8% of pitches are swinging strikes, up from 4.1% in 2012. Now, to compare to the rest of MLB: the average MLB player is swinging at 30.3% of pitches outside the strike zone, and 46.2% of all pitches. So Altuve is chasing more than average, but swinging on the whole like an average MLB player. His contact rate is still way up, comparatively: MLB players are making contact at a 79.7% clip. 

Lefties are giving him problems
One of the splits that stood out from 2012 was how Altuve excelled against left-handed pitching. Altuve hit .359/.405/.506 in 169 PAs, with 17K:10BB...with a .394 BABIP. This year, he's hitting .287/.333/.402 in 93PAs against LHPs with a much more-normal .319 BABIP. And where he tagged up lefty starters to an .866 OPS in 2012, his OPS against lefty starters in 2013 is .630, with almost a 100 point drop in BABIP. I know BABIP isn't the be-all/end-all, but that's a pretty significant regression...

...Why, his LHP/RHP splits are more in line with his rookie season, when he was seeing a lot of pitchers for the first time....sort of like switching leagues. Over his career, Altuve generally gets better the more he sees a pitcher: .667 OPS in his 1st PA, .749 in his 2nd, .732 in his 3rd. Look at his 2013 numbers in this regard: In his first PA of the game, he has a .603 OPS, .607 OPS for the 2nd PA, and .864 OPS for the 3rd PA of the game. In the 16 instances in which he sees a 4th PA from the same starting pitcher, Altuve's OPS is .866.

If we look at this collectively, Altuve has 154 PAs combining the first and second plate appearance of the game. In those 154 PAs, he's 36x144 with 35K:6BB - a .250 average with a 24.3% strikeout ratio. If we combine the 3rd and 4th PAs of the game (and this is all very simplistic), he's 33x86 - .384 - with 6K:3BB in 90 PAs, a strikeout ratio of 6.7%.

Does this mean that all we have to do is give it time? Maybe not. Since May 1, Altuve is hitting .262/.295/.330. He has more GIDPs (10) than walks (9) in that span. But I do expect him to get better as he gets familiar with the league.

It's also worth making a special note that Jimmy Paredes played Human Cannonball with Altuve on May 13, and the following day he was placed on bereavement leave due to the death of his grandmother. He missed three games and, since returning on May 18, is hitting .248/.271/.301. There's an emotional side of baseball that we tend to forget. They're not just fantasy baseball players, or video game creations that just go up and either hit or make an out.

UPDATE (with a captip to a tweet from Not Hank): 
AND PERHAPS WE SHOULD KEEP IN MIND THAT JOSE ALTUVE IS 23 YEARS OLD AND HAS ONLY 1207 PLATE APPEARANCES AND 282 MAJOR LEAGUE GAMES.