AJ Pierzynski is having his best season since he's played for the White Sox and one of the best of his career. His wOBA and OPS are the best of his White Sox career. Much of this value is secondary to his (tied for) career high batting average. Why?
Well yes part of it is luck. His BABIP is .321, his xBABIP is .306 using the THT xBABIP calculator and his career BABIP is .307. But the more interesting component of his season is that in addition to having a higher % of his batted balls fall for hits he is also putting a higher % of balls into play.
While his BB% has remained similar to career levels his K% is at its lowest rate since his one NL season, and the 2nd lowest of his career. How has he done it?
Well he hasn't done it by being more selective. AJ is currently the triple crown leader of Swinging. He leads the AL in total % of pitches swung at, % of pitches swung at in the strike zone, and % of pitches swung at outside the strike zone (amongst qualified batters). While impressive (in a wow that's interesting sort of way), this is not particularly surprising as he ranked in the top 3 in each of these categories in other years and the top 5 every year he has been with the Sox.
What he has done differently is make contact: His out-of-zone, in zone and total contact rates are all career highs. He actually ranks 15th (out of 74 qualified batters) in the AL in Contact%, making contact with 88.6% of pitches he swings at. I wonder if anyone has ever "won" the Swinging Triple Crown and still ranked in the top 15 contact hitters in the league. Whether this is a repeatabe skill or not will be worth watching next year.
So some luck and some increased contact rates have led to an amazing season by Anthony John Pierzynski.