Would you trade Jon Lester for Wil Myers?

According to Bob Dutton, of the Kansas City Star, my completely made up rumor has legs and the Royals are considering Jon Lester in exchange for Wil Myers.

The Kansas City Royals are currently looking for frontline starting pitching, and are supposedly dangling consensus #1 overall prospect Wil Myers.  Myers is coming off of a season where he hit .304/.378/.504 with 37 home runs between double and triple A.  He also won nearly every possible award for a minor league hitter, despite being young for the level.  If I had to pick one player in the minors to make an impact on the 2013 season, it would be Myers.

Lester, on the other hand, is only under contract for one year at $11.6 million, followed by a $14 million option.  During both of these years, the Red Sox are likely to be rebuilding, waiting for the crushing of your talent to arrive in the majors, led by Boegarts, Bradley, and Barnes.  Lester has been in a slow and steady decline from his spectacular 2009, as well.  Much of this may be tied to his declining velocity - he's lost a full mile per hour off his four seam fastball since 2009, but he has also moved away from his cut fastball, throwing it only 13% of the time in 2012, compared to 25% in 2011.  The reason why seems quite clear - it just wasn't getting the job done.  In 2009 and 2010 Lester's cutter was a devastating weapon, and was easily his best pitch.  In 2011 the cutter was still his best pitch, but not as effective as the previous two years, and by 2012 his cutter was below average and his worst pitch overall.  Just how exactly did Lester go from being the starter with the second best cutter in baseball to one that was well below average?

In examining the PITCHf/x data that is available from Baseball Prospectus (courtesy of Brooks Baseball), a few things jumped out at me.  First, he isn't tipping his pitches with his release point - the cutter and four seam fastball are coming out of the same window in 2010 and 2012, his best and worst year with the cutter.  What has shrunk considerably is the difference in velocity.  Just like with a changeup, a bigger difference in velocity produces better results for a cutter.  In 2010 Lester threw a 94 mile an hour fastball and a 90 mile per hour cutter, but in 2012 his fastball velocity had decline to 93.5 mph and his cutter had risen to 91 mph.  That shrinking velocity gap is worrisome, but more worrisome is the loss of movement on the pitch.  Between 2010 and 2012 Lester has lost 1" of horizontal movement and 2" of vertical movement differential between his cutter and four seam fastball.  This loss of movement and velocity differential has led to an elevated home run per fly ball rate for the cutter, rising from a miniscule 2.3% in 2010 to 11.3%.

The million (multi-million really) dollar question is what is at the root of this change?  If you think it is something fixable, then the Red Sox should probably just hang on to Lester.  Unfortunately, there isn't anything in the numbers that jumps out as an easy fix, such as an inconsistent release point.  If the Royals are dead set on trading for a frontline starter, and Myers is on the table, then the Red Sox need to be talking to them.  Given that Lester is coming off a down year, he might not even be enough for Myers, but former top prospect Eric Hosmer is coming off of a down year and could be an intriguing fit for the Red Sox, who have a massive hole to fill at first base for the next five years.  The Red Sox probably don't want to give the impression that they're blowing the team up, but the opportunity to add a young, impact hitter should have Cherington pondering just how much of a PR hit he's willing to take for the long term outlook of the franchise.