I’ve got a pair of articles at BP and ESPN Insider focusing on young players whom PECOTA forecasts to break out, which in terms of our forecasting system means improving their productivity at least 20 percent relative to their three-year baseline. From the hitters piece (BP and ESPN):

Not every top prospect hits the ground running the way recent Rookie of the Year winners like Evan Longoria and Ryan Braun did, stepping into a major league lineup and putting up All-Star caliber numbers. Sometimes it takes a couple of years’ worth of experience and adjustments for a high-upside player to reach his potential, but when he does, look out.

Our PECOTA projection system can help to identify such players via a trio of categories called “breakout,” “improve” and “decline,” which estimate the likelihood of a player’s production significantly rising or falling relative to his established baseline level. “Breakout rate” is the percent chance that a hitter’s equivalent runs produced per plate appearance will improve by at least 20 percent relative to the weighted average of his performance over the past three years. A high rate generally indicates a high upside, though it’s worth noting the Ugueto Effect, in which the system will estimate a high rate for a horrible player simply because there’s nowhere else for him to go.

What follows are a handful of players — curiously concentrated among a small number of teams — whom PECOTA sees as excellent breakout candidates at the major league level this year, with “breakout rates” of at least 33 percent. Each is forecast for at least 400 plate appearances, a .275 “equivalent average,” and 2.5 WARP. Most are familiar names from our recent top 100 prospects lists whom you’ll likely hear even more about as they approach their considerable potentials.

The hitters most likely to breakout inclue Justin Upton, Elijah Dukes, Chris Young, Lastings Milledge, Ryan Zimmerman, Edwin Encarnacion, Jay Bruce and Adam Jones.

The pitchers (BP and ESPN) include Andrew Miller, Clay Buchholz, Anibal Sanchez, Clayton Kershaw, John Danks, Jonathan Sanchez, Max Scherzer and Justin Masterson. Here’s what I had to say about Kershaw and Danks:

Clayton Kershaw, Dodgers (157 IP, 4.35 EqERA, 23% Breakout Rate)
Drafted one pick behind [Andrew] Miller, Kershaw ranked fifth on last year’s prospect list, and dazzled observers in spring training — all before celebrating his 20th birthday. Recalled last May, he scuffled in his first major league stint before undertaking a Double-A refresher course. Upon returning, the young southpaw exhibited much-improved control (67/28 K/BB ratio in 69 innings) and impressive poise, finishing with a respectable 4.26 ERA that would have been considerably lower with average defensive support. Only the speed of his ascent curbs PECOTA’s optimism for him to maintain or better last year’s level, since his baseline includes relatively high translated ERAs from his low minors work.

John Danks, White Sox (169 IP, 4.03 EqERA, 20% Breakout Rate)
By any conventional sense of the term, Danks already broke out in 2008, pitching the White Sox into the postseason in the Game 163 tiebreaker to cap a season in which he finished fifth in the AL with a 3.32 ERA. His projection is weighted down by the brutal translations of his 2006 performance and an ugly rookie campaign, but the addition of a cut fastball to his arsenal last year boosted his ground-ball rate and prevented homers, and typifies the non-linear gains which developing pitchers often deliver. PECOTA remains bullish.

Sorry, Yankee fans, Phil Hughes just missed the list. His breakout rate of 48 percent is higher than any pitcher on the list, but his weighted mean projected ERA is 4.74, 0.14 above my cutoff.