Chris Young is a hard player to figure out, year after year. His rookie year in 2007 saw him get 32 home runs and almost 30 steals, and the performance earned him a healthy raise. The next 2 years were the complete opposite in production. The power was still there, but strikeouts weighed him down and he could seemingly not put the ball in the field regularly. His uneven performance was widely debated by Diamondbacks fans, and it resulted in a short demotion in 2009 to AAA (a season where he hit .212).
He did finally bounce back in 2010 with an All-Star bid, having more of a season that people expected when he signed his new contract after 2007, but 2011 could be considered a disappointment. He was hampered by injuries, especially at the end of the season, but it's still disappointing.
In 2012 he's off to tremendous tear, sitting on a slash line of .405/.500/.892, 5 home runs, and 13 runs batted in, all with only 5 strikeouts. Obviously he's not going to stay at this clip for the season, but the question is how much of a decline can we expect?
It's hard to be particularly confident over 10 games, as it's not surprising for a player to go on a 10 game tear or a 10 game slump. We should expect the ratio stats to slow down, simply because he's never hit anywhere near those numbers, and it's incredibly difficult, and therefore unlikely, to hit .400 for a season. It's only been done 35 times since organized baseball as we know it formed, and it hasn't been seen since 1941.
And we have reason to be suspicious of the hot start. The first number to look at is his BABIP, or batting average on balls in play. There isn't some standard number, though most players are around .300, but you can compare a player's current BABIP to his career BABIP and see if there's just an unusual amount of luck. It's bad news for Young, who has a BABIP of 100 points higher than his career average (.370 vs .281). The amount of balls he's able to put into play is going to drop, especially since he's normally below average in this area.
The biggest thing he's done so far to put balls in play is avoid the strikeout. His career strikeout % is a little bit above 20%, and going as high as 26.5% in his difficult 2009 season. This year his 5 strikeouts are good enough to halve his strikeout % to 11.4. He's only walking more, and the walk/strikeout ratio has jumped considerably over where he normally sits (he's doubled it this year to 1.2).
So by a combination of regression (remember, extreme performances for good or bad have a tendency to move back towards the mean), and the above measures, Chris Young should fall back to earth to a certain extent. He's still going to have a good season, even if you just accept his preseason projections, but we don't know how good yet.
One thing we could do to try to predict is take his current numbers, preseason predicted numbers, and then weight each side to see how much his starting performance might affect his ending numbers.
Season numbers = (10 game number)(.0617) + (ZiPS)(.9383)
As hot a start as he's had, it's not enough to turn a projected .250 batting average into .350. It did move the needle, though. His projected slash line from ZiPS was .249/.340/.456. His new projection is .259/.350/.483. We can continue to look at this over the season, as the longer the season goes and the longer he can maintain this pace, the more of an impact it should have on his final numbers.
Still, even if and when he falls off the pace, he's currently looking at ending with his best ever season. We should enjoy his torrid pace now, be unsurprised if doesn't continue, and be thankful the Diamondbacks have a guy like Young in center field.