This year has been a miles-deep cesspool of suck. We can mostly all agree upon that. What hurts the most is that our core players have seemingly all have bad years; Castro's struggles have been well documented, as have Rizzo's. Shark still flashes dominance, but at the end of the year he still has a 3.69 FIP and a 4.29 ERA. I've never considered Darwin Barney a core piece, but if you did, he's batting .215/.272/.319 for a .259 wOBA, 56 wRC+. Travis Wood is .233/.258/.400 this year, for a .287 wOBA and a 75 wRC+ (I'd seriously consider pinch-hitting Wood for Barney, though Barney is still a slightly better hitter).
There are a few bright spots this year, though. Travis Wood has been dealing this year (though solidly outperforming his peripherals). He's done better than I expected. Welington Castillo has improved markedly on defense, and maintained his league-average production at the plate (which has a good amount of value as a catcher). These are two bright spots, but we could have expected them, at least sort of.
What I'm not sure ANYONE expected, though, was the very solid play of Junior Lake. He came on like gangbusters after his callup, and then cooled off considerably. This isn't uncommon; many players fail to adjust to the league that adjusts to them. Fortunately for Cubs fans, it seems like Lake has figured it out, at least a little bit. Over 206 PA, he has a .313/.356/.474 line, which is good enough for a .363 wOBA and a 128 wRC+. He's even been a plus fielder; add it all up, and he's had 1.4 fWAR on the season. He also has 1.4 WARP.
His great season is of course predicated on a few things. For one, his BABIP is .394. That looks crazy high at first blush, but his minor league BABIP is right around .350. That BABIP will fall, but not as much as one might think. He's also hitting 27.1% of his batted balls for line drives; that's way higher than the league average, and comparable to hitters like Joey Votto and Austin Jackson. I'm not saying he can't put up similar rates in the future (and LD% is the primary driver of a high BABIP, which is why the slow Votto can have a BABIP of .364 this year), but it seems high, given where he is as a player.
206 PA isn't a ton, but it's enough to give us some idea of what Lake's true talent level might be. He's currently batting .313. He can say with a 95% confidence interval that the minimum "true talent" of that performance is .250, and the highest is .376. I think he's got a good shot to settle into a .275/.310/.430 level next year, which I'll definitely take. It's not sexy, but the average CF line this year is .260/.326/.398.
Long-term, Junior Lake probably isn't the answer at any one position, but he's shown so far this year that he's not going to embarrass himself at the majors. He should get the first look at CF next year (above Sweeney if he re-signs), and I'm mildly confident that he'll earn that job. Who would have thought?